U.S. Supreme Court United States v. Leon, 468
U.S. 897 (1984) United States v. Leon No. 82-1771 Argued January 17,
1984 Decided July 5, 1984 468
U.S. 897 CERTIORARI TO THE UNITED STATES
COURT OF APPEALS FOR THE NINTH CIRCUIT Syllabus Acting on the basis of information from a confidential
informant, officers of the Burbank, Cal., Police Department
initiated a drug-trafficking investigation involving surveillance
of respondents' activities. Based on an affidavit summarizing the
police officers' observations, Officer Rombach prepared an
application for a warrant to search three residences and
respondents' automobiles for an extensive list of items. The
application w as reviewed by several Deputy District Attorneys, and
a facially valid search warrant was issued by a state court judge.
Ensuing searches produced large quantities of drugs and other
evidence. Respondents were indicted for federal drug offenses, and
filed motions to suppress the evidence seized pursuant to the
warrant. After an evidentiary hearing, the District Court granted
the motions in part, concluding that the affidavit was insufficient
to establish probable cause. Although recognizing that Officer
Rombach had acted in good faith, the court rejected the
Government's suggestion that the Fourth Amendment exclusionary rule
should not apply where evidence is seized in reasonable, good faith
reliance on a search warrant. The Court of Appeals affirmed, also
refusing the Government's invitation to recognize a good faith
exception to the rule. The Government's petition for certiorari
presented only the question whether a good faith exception to the
exclusionary rule should be recognized. Held: 1. The Fourth Amendment exclusionary rule should not be applied
so as to bar the use in the prosecution's case in chief of evidence
obtained by officers acting in reasonable reliance on a search
warrant issued by a detached and neutral magistrate but ultimately
found to be invalid. Pp. 468 U. S.
905 -925.

															(a) An examination of the Fourth Amendment's origin and purposes
makes clear that the use of fruits of a past unlawful search or
seizure works no new Fourth Amendment wrong. The question whether
the exclusionary sanction is appropriately imposed in a particular
case as a judicially created remedy to safeguard Fourth Amendment
rights through its deterrent effect, must be resolved by weighing
the costs and benefits of preventing the use in the prosecution's
case in chief of inherently trustworthy tangible evidence.
Indiscriminate application of the Page 468 U. S. 898 exclusionary rule -- impeding the criminal justice system's
truthfinding function and allowing some guilty defendants to go
free -- may well generate disrespect for the law and the
administration of justice. Pp. 468
U.S. 906 -908.

															(b) Application of the exclusionary rule should continue where a
Fourth Amendment violation has been substantial and deliberate, but
the balancing approach that has evolved in determining whether the
rule should be applied in a variety of contexts -- including
criminal trials -- suggests that the rule should be modified to
permit the introduction of evidence obtained by officers reasonably
relying on a warrant issued by a detached and neutral magistrate.
Pp. 468 U. S.
908 -913.

															(c) The deference accorded to a magistrate's finding of probable
cause for the issuance of a warrant does not preclude inquiry into
the knowing or reckless falsity of the affidavit on which that
determination was based, and the courts must also insist that the
magistrate purport to perform his neutral and detached function and
not serve merely as a rubber stamp for the police. Moreover,
reviewing courts will not defer to a warrant based on an affidavit
that does not provide the magistrate with a substantial basis for
determining the existence of probable cause. However, the
exclusionary rule is designed to deter police misconduct, rather
than to punish the errors of judges and magistrates. Admitting
evidence obtained pursuant to a warrant while at the same time
declaring that the warrant was somehow defective will not reduce
judicial officers' professional incentives to comply with the
Fourth Amendment, encourage them to repeat their mistakes, or lead
to the granting of all colorable warrant requests. Pp. 468 U. S.
913 -917.

															(d) Even assuming that the exclusionary rule effectively deters
some police misconduct and provides incentives for the law
enforcement profession as a whole to conduct itself in accord with
the Fourth Amendment, it cannot be expected, and should not be
applied, to deter objectively reasonable law enforcement activity.
In the ordinary case, an officer cannot be expected to question the
magistrate's probable cause determination or his judgment that the
form of the warrant is technically sufficient . Once the warrant
issues, there is literally nothing more the policeman can do in
seeking to comply with the law, and penalizing the officer for the
magistrate's error, rather than his own, cannot logically
contribute to the deterrence of Fourth Amendment violations. Pp. 468 U. S.
918 -921.

															(e) A police officer's reliance on the magistrate's probable
cause determination and on the technical sufficiency of the warrant
he issues must be objectively reasonable. Suppression remains an
appropriate remedy if the magistrate or judge in issuing a warrant
was misled by information in an affidavit that the affiant knew was
false or would have known was false except for his reckless
disregard of the truth, or if the Page 468 U. S. 899 issuing magistrate wholly abandoned his detached and neutral
judicial role. Nor would an officer manifest objective good faith
in relying on a warrant based on an affidavit so lacking in indicia
of probable cause as to render official belief in its existence
entirely unreasonable. Finally, depending on the circumstances of
the particular case, a warrant may be so facially deficient -- i.e., in failing to particularize the place to be searched
or the things to be seized -- that the executing officers cannot
reasonably presume it to be valid. Pp. 468 U. S.
922 -925.

															2. In view of the modification of the exclusionary rule, the
Court of Appeals' judgment cannot stand in this case. Only
respondent Leon contended that no reasonably well trained police
officer could have believed that there existed probable cause to
search his house. However, the record establishes that the police
officers' reliance on the state court judge's determination of
probable cause was objectively reasonable. Pp. 925-926.

															701 F.2d 187, reversed.

															WHITE, J., delivered the opinion of the Court, in which BURGER,
C.J., and BLACKMUN, POWELL, REHNQUIST, and O'CONNOR, JJ., joined.
BLACKMUN, J., filed a concurring opinion, post, p. 468 U. S. 927 .
BRENNAN, J., filed a dissenting opinion, in which MARSHALL, J.,
joined, post, p. 468 U. S. 928 .
STEVENS, J., filed a dissenting opinion, post, p. 468 U. S.
960 . Page 468 U. S. 900 JUSTICE WHITE delivered the opinion of the Court.

															This case presents the question whether the Fourth Amendment
exclusionary rule should be modified so as not to bar the use in
the prosecution's case in chief of evidence obtained by officers
acting in reasonable reliance on a search warrant issued by a
detached and neutral magistrate but ultimately found to be
unsupported by probable cause. To resolve this question, we must
consider once again the tension between the sometimes competing
goals of, on the one hand, deterring official misconduct and
removing inducements to unreasonable invasions of privacy and, on
the other, establishing procedures under which criminal defendants
are "acquitted Page 468 U. S. 901 or convicted on the basis of all the evidence which exposes the
truth." Alderman v. United States, 394 U.
S. 165 , 394 U. S. 175 (1969). I In August, 1981, a confidential informant of unproven
reliability informed an officer of the Burbank Police Department
that two persons known to him as "Armando" and "Patsy" were selling
large quantities of cocaine and methaqualone from their residence
at 620 Price Drive in Burbank, Cal. The informant also indicated
that he had witnessed a sale of methaqualone by "Patsy" at the
residence approximately five months earlier, and had observed at
that time a shoebox containing a large amount of cash that belonged
to "Patsy." He further declared that "Armando" and "Patsy"
generally kept only small quantities of drugs at their residence
and stored the remainder at another location in Burbank.

															On the basis of this information, the Burbank police initiated
an extensive investigation focusing first on the Price Drive
residence and later on two other residences as well. Cars parked at
the Price Drive residence were determined to belong to respondents
Armando Sanchez, who had previously been arrested for possession of
marihuana, and Patsy Stewart, who had no criminal record. During
the course of the investigation, officers observed an automobile
belonging to respondent Ricardo Del Castillo, who had previously
been arrested for possession of 50 pounds of marihuana, arrive at
the Price Drive residence. The driver of that car entered the
house, exited shortly thereafter carrying a small paper sack, and
drove away. A check of Del Castillo's probation records led the
officers to respondent Alberto Leon, whose telephone number Del
Castillo had listed as his employer's. Leon had been arrested in
1980 on drug charges, and a companion had informed the police at
that time that Leon was heavily involved in the importation of
drugs into this country. Before the current investigation began,
the Burbank officers had Page 468 U. S. 902 learned that an informant had told a Glendale police officer
that Leon stored a large quantity of methaqualone at his residence
in Glendale. During the course of this investigation, the Burbank
officers learned that Leon was living at 716 South Sunset Canyon in
Burbank.

															Subsequently, the officers observed several persons, at least
one of whom had prior drug involvement, arriving at the Price Drive
residence and leaving with small packages; observed a variety of
other material activity at the two residences as well as at a
condominium at 7902 Via Magdalena; and witnessed a variety of
relevant activity involving respondents' automobiles. The officers
also observed respondents Sanchez and Stewart board separate
flights for Miami. The pair later returned to Los Angeles together,
consented to a search of their luggage that revealed only a small
amount of marihuana, and left the airport. Based on these and other
observations summarized in the affidavit, App. 34, Officer Cyril
Rombach of the Burbank Police Department, an experienced and
well-trained narcotics investigator, prepared an application for a
warrant to search 620 Price Drive, 716 South Sunset Canyon, 7902
Via Magdalena, and automobiles registered to each of the
respondents for an extensive list of items believed to be related
to respondents' drug trafficking activities. Officer Rombach's
extensive application was reviewed by several Deputy District
Attorneys.

															A facially valid search warrant was issued in September, 1981,
by a State Superior Court Judge. The ensuing searches produced
large quantities of drugs at the Via Magdalena and Sunset Canyon
addresses and a small quantity at the Price Drive residence. Other
evidence was discovered at each of the residences and in Stewart's
and Del Castillo's automobiles. Respondents were indicted by a
grand jury in the District Court for the Central District of
California and charged with conspiracy to possess and distribute
cocaine and a variety of substantive counts. Page 468 U. S. 903 The respondents then filed motions to suppress the evidence
seized pursuant to the warrant. [ Footnote 1 ] The District Court held an evidentiary hearing
and, while recognizing that the case was a close one, see
id. at 131, granted the motions to suppress in part. It
concluded that the affidavit was insufficient to establish probable
cause, [ Footnote 2 ] but did not
suppress all of the evidence as to all of the respondents because
none of the respondents had standing to challenge all of the
searches. [ Footnote 3 ] In Page 468 U. S. 904 response to a request from the Government, the court made clear
that Officer Rombach had acted in good faith, but it rejected the
Government's suggestion that the Fourth Amendment exclusionary rule
should not apply where evidence is seized in reasonable, good faith
reliance on a search warrant. [ Footnote 4 ] The District Court denied the Government's
motion for reconsideration, id. at 147, and a divided
panel of the Court of Appeals for the Ninth Circuit affirmed,
judgt. order reported at 701 F.2d 187 (1983). The Court of Appeals
first concluded that Officer Rombach's affidavit could not
establish probable cause to search the Price Drive residence. To
the extent that the affidavit set forth facts demonstrating the
basis of the informant's knowledge of criminal activity, the
information included was fatally stale. The affidavit, moreover,
failed to establish the informant's credibility. Accordingly, the
Court of Appeals concluded that the information provided by the
informant was inadequate under both prongs of the two-part test
established in Aguilar v. Texas, 378 U.
S. 108 (1964), and Spinelli v. United States, 393 U. S. 410 (1969). [ Footnote 5 ] The
officers' independent investigation neither cured the staleness nor
corroborated the details of the informant's declarations. The Court
of Appeals then considered whether the affidavit formed a proper
basis for the Page 468 U. S. 905 search of the Sunset Canyon residence. In its view, the
affidavit included no facts indicating the basis for the
informants' statements concerning respondent Leon's criminal
activities, and was devoid of information establishing the
informants' reliability. Because these deficiencies had not been
cured by the police investigation, the District Court properly
suppressed the fruits of the search. The Court of Appeals refused
the Government's invitation to recognize a good faith exception to
the Fourth Amendment exclusionary rule. App. to Pet. for Cert.
4a.

															The Government's petition for certiorari expressly declined to
seek review of the lower courts' determinations that the search
warrant was unsupported by probable cause, and presented only the
question

															"[w]hether the Fourth Amendment exclusionary rule should be
modified so as not to bar the admission of evidence seized in
reasonable, good faith reliance on a search warrant that is
subsequently held to be defective."

															We granted certiorari to consider the propriety of such a
modification. 463 U.S. 1206 (1983). Although it undoubtedly is
within our power to consider the question whether probable cause
existed under the "totality of the circumstances" test announced
last Term in Illinois v. Gates, 462 U.
S. 213 (1983), that question has not been briefed or
argued; and it is also within our authority, which we choose to
exercise, to take the case as it comes to us, accepting the Court
of Appeals' conclusion that probable cause was lacking under the
prevailing legal standards. See this Court's Rule 21.
1(a).

															We have concluded that, in the Fourth Amendment context, the
exclusionary rule can be modified somewhat without jeopardizing its
ability to perform its intended functions. Accordingly, we reverse
the judgment of the Court of Appeals. II Language in opinions of this Court and of individual Justices
has sometimes implied that the exclusionary rule is a necessary
corollary of the Fourth Amendment, Mapp
v. Page 468 U. S. 906 Ohio, 367 U. S. 643 , 367 U. S. 651 ,
655-657 (1961); Olmstead v. United States, 277 U.
S. 438 , 277 U. S.
462 -463 (1928), or that the rule is required by the
conjunction of the Fourth and Fifth Amendments. Mapp v. Ohio,
supra, at 367 U. S.
661 -662 (Black, J., concurring); Agnello v. United
States, 269 U. S. 20 , 269 U. S. 33 -34
(1925). These implications need not detain us long. The Fifth
Amendment theory has not withstood critical analysis or the test of
time, see Andresen v. Maryland, 427 U.
S. 463 (1976), and the Fourth Amendment "has never been
interpreted to proscribe the introduction of illegally seized
evidence in all proceedings or against all persons." Stone v.
Powell, 428 U. S. 465 , 428 U. S. 486 (1976). A The Fourth Amendment contains no provision expressly precluding
the use of evidence obtained in violation of its commands, and an
examination of its origin and purposes makes clear that the use of
fruits of a past unlawful search or seizure "work[s] no new Fourth
Amendment wrong." United States v. Calandra, 414 U.
S. 338 , 414 U. S. 354 (1974). The wrong condemned by the Amendment is "fully
accomplished" by the unlawful search or seizure itself, ibid., and the exclusionary rule is neither intended nor
able to "cure the invasion of the defendant's rights which he has
already suffered." Stone v. Powell, supra, at 428 U. S. 540 (WHITE, J., dissenting). The rule thus operates as "a judicially
created remedy designed to safeguard Fourth Amendment rights
generally through its deterrent effect, rather than a personal
constitutional right of the party aggrieved." United States v.
Calandra, supra, at 414 U. S.
348 .

															Whether the exclusionary sanction is appropriately imposed in a
particular case, our decisions make clear, is

															"an issue separate from the question whether the Fourth
Amendment rights of the party seeking to invoke the rule were
violated by police conduct." Illinois v. Gates, supra, at 462 U. S. 223 .
Only the former question is currently before us, and it must Page 468 U. S. 907 be resolved by weighing the costs and benefits of preventing the
use in the prosecution's case in chief of inherently trustworthy
tangible evidence obtained in reliance on a search warrant issued
by a detached and neutral magistrate that ultimately is found to be
defective.

															The substantial social costs exacted by the exclusionary rule
for the vindication of Fourth Amendment rights have long been a
source of concern.

															"Our cases have consistently recognized that unbending
application of the exclusionary sanction to enforce ideals of
governmental rectitude would impede unacceptably the truthfinding
functions of judge and jury." United States v. Payner, 447 U.
S. 727 , 447 U. S. 734 (1980). An objectionable collateral consequence of this
interference with the criminal justice system's truthfinding
function is that some guilty defendants may go free or receive
reduced sentences as a result of favorable plea bargains. [ Footnote 6 ] Particularly Page 468 U. S. 908 when law enforcement officers have acted in objective good faith
or their transgressions have been minor, the magnitude of the
benefit conferred on such guilty defendants offends basic concepts
of the criminal justice system. Stone v. Powell, 428 U.S.
at 428 U. S. 490 .
Indiscriminate application of the exclusionary rule, therefore, may
well "generat[e] disrespect for the law and administration of
justice." Id. at 428 U. S. 491 .
Accordingly,

															"[a]s with any remedial device, the application of the rule has
been restricted to those areas where its remedial objectives are
thought most efficaciously served." United States v. Calandra, supra, at 414 U. S. 348 ; see Stone v. Powell, supra, at 428 U. S.
486 -487; United States v. Janis, 428 U.
S. 433 , 428 U. S. 447 (1976). B Close attention to those remedial objectives has characterized
our recent decisions concerning the scope of the Fourth Amendment
exclusionary rule. The Court has, to be sure, not seriously
questioned,

															"in the absence of a more efficacious sanction, the continued
application of the rule to suppress evidence Page 468 U. S. 909 from the [prosecution's] case where a Fourth Amendment violation
has been substantial and deliberate. . . ." Franks v. Delaware, 438 U. S. 154 , 438 U. S. 171 (1978); Stone v. Powell, supra, at 428 U. S. 492 .
Nevertheless, the balancing approach that has evolved in various
contexts -- including criminal trials --

															"forcefully suggest[s] that the exclusionary rule be more
generally modified to permit the introduction of evidence obtained
in the reasonable good faith belief that a search or seizure was in
accord with the Fourth Amendment." Illinois v. Gates, 462 U.S. at 462 U. S. 255 (WHITE, J., concurring in judgment).

															In Stone v. Powell, supra, the Court emphasized the
costs of the exclusionary rule, expressed its view that limiting
the circumstances under which Fourth Amendment claims could be
raised in federal habeas corpus proceedings would not reduce the
rule's deterrent effect, id. at 428 U. S.
489 -495, and held that a state prisoner who has been
afforded a full and fair opportunity to litigate a Fourth Amendment
claim may not obtain federal habeas relief on the ground that
unlawfully obtained evidence had been introduced at his trial. Cf. Rose v. Mitchell, 443 U. S. 545 , 443 U. S.
560 -563 (1979). Proposed extensions of the exclusionary
rule to proceedings other than the criminal trial itself have been
evaluated and rejected under the same analytic approach. In United States v. Calandra, for example, we declined to
allow grand jury witnesses to refuse to answer questions based on
evidence obtained from an unlawful search or seizure, since "[a]ny
incremental deterrent effect which might be achieved by extending
the rule to grand jury proceedings is uncertain, at best." 414 U.S.
at 414 U. S. 348 .
Similarly, in United States v. Janis, supra, we permitted
the use in federal civil proceedings of evidence illegally seized
by state officials, since the likelihood of deterring police
misconduct through such an extension of the exclusionary rule was
insufficient to outweigh its substantial social costs. In so doing,
we declared that,

															"[i]f . . . the exclusionary rule does not result in appreciable
deterrence, then, clearly, its use in the instant situation is
unwarranted." Id. at 428 U. S.
454 . Page 468 U. S. 910 As cases considering the use of unlawfully obtained evidence in
criminal trials themselves make clear, it does not follow from the
emphasis on the exclusionary rule's deterrent value that "anything
which deters illegal searches is thereby commanded by the Fourth
Amendment." Alderman v. United States, 394 U.S. at 394 U. S. 174 .
In determining whether persons aggrieved solely by the introduction
of damaging evidence unlawfully obtained from their coconspirators
or codefendants could seek suppression, for example, we found that
the additional benefits of such an extension of the exclusionary
rule would not outweigh its costs. Id. at 394 U. S.
174 -175. Standing to invoke the rule has thus been
limited to cases in which the prosecution seeks to use the fruits
of an illegal search or seizure against the victim of police
misconduct. Rakas v. Illinois, 439 U.
S. 128 (1978); Brown v. United States, 411 U. S. 223 (1973); Wong Sun v. United States, 371 U.
S. 471 , 371 U. S.
491 -492 (1963). Cf. United States v. Payner, 447 U. S. 727 (1980).

															Even defendants with standing to challenge the introduction in
their criminal trials of unlawfully obtained evidence cannot
prevent every conceivable use of such evidence. Evidence obtained
in violation of the Fourth Amendment and inadmissible in the
prosecution's case in chief may be used to impeach a defendant's
direct testimony. Walder v. United States, 347 U. S.
62 (1954). See also Oregon v. Hass, 420 U. S. 714 (1975); Harris v. New York, 401 U.
S. 222 (1971). A similar assessment of the "incremental
furthering" of the ends of the exclusionary rule led us to conclude
in United States v. Havens, 446 U.
S. 620 , 446 U. S. 627 (1980), that evidence inadmissible in the prosecution's case in
chief or otherwise as substantive evidence of guilt may be used to
impeach statements made by a defendant in response to "proper
cross-examination reasonably suggested by the defendant's direct
examination." Id. at 446 U. S.
627 -628.

															When considering the use of evidence obtained in violation of
the Fourth Amendment in the prosecution's case in chief, moreover,
we have declined to adopt a per se or "but for" rule Page 468 U. S. 911 that would render inadmissible any evidence that came to light
through a chain of causation that began with an illegal arrest. Brown v. Illinois, 422 U. S. 590 (1975); Wong Sun v. United States, supra, at 371 U. S.
487 -488. We also have held that a witness' testimony may
be admitted even when his identity was discovered in an
unconstitutional search. United States v. Ceccolini, 435 U. S. 268 (1978). The perception underlying these decisions -- that the
connection between police misconduct and evidence of crime may be
sufficiently attenuated to permit the use of that evidence at trial
-- is a product of considerations relating to the exclusionary rule
and the constitutional principles it is designed to protect. Dunaway v. New York, 442 U. S. 200 , 442 U. S.
217 -218 (1979); United States v. Ceccolini,
supra, at 435 U. S. 279 .
[ Footnote 7 ] In short, the
"dissipation of the taint" concept that the Court has applied in
deciding whether exclusion is appropriate in a particular case

															"attempts to mark the point at which the detrimental
consequences of illegal police action become so attenuated that the
deterrent effect of the exclusionary rule no longer justifies its
cost." Brown v. Illinois, supra, at 411 U. S. 609 (POWELL, J., concurring in part). Not surprisingly in view of this
purpose, an assessment of the flagrancy of the police misconduct
constitutes an important step in the calculus. Dunaway v. New
York, supra, at 442 U. S. 218 ; Brown v. Illinois, supra, at 411 U. S.
603 -604.

															The same attention to the purposes underlying the exclusionary
rule also has characterized decisions not involving the scope of
the rule itself. We have not required suppression of the fruits of
a search incident to an arrest made in good faith reliance on a
substantive criminal statute that subsequently Page 468 U. S. 912 is declared unconstitutional. Michigan v. DeFillippo, 443 U. S. 31 (1979). [ Footnote 8 ] Similarly,
although the Court has been unwilling to conclude that new Fourth
Amendment principles are always to have only prospective effect, United States v. Johnson, 457 U.
S. 537 , 457 U. S. 560 (1982), [ Footnote 9 ] no Fourth
Amendment decision marking a "clear break with the past" has been
applied retroactively. See United States v. Peltier, 422 U. S. 531 (1975); Desist v. United States, 394 U.
S. 244 (1969); Linkletter v. Walker, 381 U. S. 618 (1965). [ Footnote 10 ] The
propriety Page 468 U. S. 913 of retroactive application of a newly announced Fourth Amendment
principle, moreover, has been assessed largely in terms of the
contribution retroactivity might make to the deterrence of police
misconduct. United States v. Johnson, supra, at 457 U. S.
560 -561; United States v. Peltier, supra, at 422 U. S.
536 -539, 422 U. S.
542 .

															As yet, we have not recognized any form of good faith exception
to the Fourth Amendment exclusionary rule. [ Footnote 11 ] But the balancing approach that has
evolved during the years of experience with the rule provides
strong support for the modification currently urged upon us. As we
discuss below, our evaluation of the costs and benefits of
suppressing reliable physical evidence seized by officers
reasonably relying on a warrant issued by a detached and neutral
magistrate leads to the conclusion that such evidence should be
admissible in the prosecution's case in chief. III A Because a search warrant

															"provides the detached scrutiny of a neutral magistrate, which
is a more reliable safeguard Page 468 U. S. 914 against improper searches than the hurried judgment of a law
enforcement officer 'engaged in the often competitive enterprise of
ferreting out crime,'" United States v. Chadwick, 433 U. S.
1 , 433 U. S. 9 (1977)
(quoting Johnson v. United States, 333 U. S.
10 , 333 U. S. 14 (1948)), we have expressed a strong preference for warrants, and
declared that, "in a doubtful or marginal case, a search under a
warrant may be sustainable where without one it would fall." United States v. Ventresca, 380 U.
S. 102 , 380 U. S. 106 (1965). See Aguilar v. Texas, 378 U.S. at 378 U. S. 111 .
Reasonable minds frequently may differ on the question whether a
particular affidavit establishes probable cause, and we have thus
concluded that the preference for warrants is most appropriately
effectuated by according "great deference" to a magistrate's
determination. Spinelli v. United States, 393 U.S. at 393 U. S. 419 . See Illinois v. Gates, 462 U.S. at 462 U. S. 236 ; United States v. Ventresca, supra, at 380 U. S.
108 -109.

															Deference to the magistrate, however, is not boundless. It is
clear, first, that the deference accorded to a magistrate's finding
of probable cause does not preclude inquiry into the knowing or
reckless falsity of the affidavit on which that determination was
based. Franks v. Delaware, 438 U.
S. 154 (1978). [ Footnote 12 ] Second, the courts must also insist that the
magistrate purport to "perform his neutral and detached'
function and not serve merely as a rubber stamp for the police." Aguilar v. Texas, supra, at 378 U. S. 111 . See Illinois v. Gates, supra, at 462 U. S. 239 .
A magistrate failing to "manifest that neutrality and detachment
demanded of a judicial officer when presented with a warrant
application" and who acts instead as "an adjunct law enforcement
officer" cannot provide valid authorization for an otherwise
unconstitutional search. Lo-Ji Sales, Inc. v. New York, 442 U. S. 319 , 442 U. S.
326 -327 (1979). Page 468 U. S. 915 Third, reviewing courts will not defer to a warrant based on an
affidavit that does not "provide the magistrate with a substantial
basis for determining the existence of probable cause." Illinois v. Gates, 462 U.S. at 462 U. S.
239 .

															"Sufficient information must be presented to the magistrate to
allow that official to determine probable cause; his action cannot
be a mere ratification of the bare conclusions of others." Ibid. See Aguilar v. Texas, supra, at 378 U. S.
114 -115; Giordenello v. United States, 357 U. S. 480 (1958); Nathanson v. United States, 290 U. S.
41 (1933). [ Footnote
13 ] Even if the warrant application was supported by more than
a "bare bones" affidavit, a reviewing court may properly conclude
that, notwithstanding the deference that magistrates deserve, the
warrant was invalid because the magistrate's probable cause
determination reflected an improper analysis of the totality of the
circumstances, Illinois v. Gates, supra, at 462 U. S.
238 -239, or because the form of the warrant was improper
in some respect.

															Only in the first of these three situations, however, has the
Court set forth a rationale for suppressing evidence obtained
pursuant to a search warrant; in the other areas, it has simply
excluded such evidence without considering whether Page 468 U. S. 916 Fourth Amendment interests will be advanced. To the extent that
proponents of exclusion rely on its behavioral effects on judges
and magistrates in these areas, their reliance is misplaced. First,
the exclusionary rule is designed to deter police misconduct,
rather than to punish the errors of judges and magistrates. Second,
there exists no evidence suggesting that judges and magistrates are
inclined to ignore or subvert the Fourth Amendment, or that
lawlessness among these actors requires application of the extreme
sanction of exclusion. [ Footnote
14 ]

															Third, and most important, we discern no basis, and are offered
none, for believing that exclusion of evidence seized pursuant to a
warrant will have a significant deterrent effect on the issuing
judge or magistrate. [ Footnote
15 ] Many of the factors Page 468 U. S. 917 that indicate that the exclusionary rule cannot provide an
effective "special" or "general" deterrent for individual offending
law enforcement officers [ Footnote 16 ] apply as well to judges or magistrates. And,
to the extent that the rule is thought to operate as a "systemic"
deterrent on a wider audience, [ Footnote 17 ] it clearly can have no such effect on
individuals empowered to issue search warrants. Judges and
magistrates are not adjuncts to the law enforcement team; as
neutral judicial officers, they have no stake in the outcome of
particular criminal prosecutions. The threat of exclusion thus
cannot be expected significantly to deter them. Imposition of the
exclusionary sanction is not necessary meaningfully to inform
judicial officers of their errors, and we cannot conclude that
admitting evidence obtained pursuant to a warrant while at the same
time declaring that the warrant was somehow defective will in any
way reduce judicial officers' professional incentives to comply
with the Fourth Amendment, encourage them to repeat their mistakes,
or lead to the granting of all colorable warrant requests.
[ Footnote 18 ] Page 468 U. S. 918 B If exclusion of evidence obtained pursuant to a subsequently
invalidated warrant is to have any deterrent effect, therefore, it
must alter the behavior of individual law enforcement officers or
the policies of their departments. One could argue that applying
the exclusionary rule in cases where the police failed to
demonstrate probable cause in the warrant application deters future
inadequate presentations or "magistrate shopping," and thus
promotes the ends of the Fourth Amendment. Suppressing evidence
obtained pursuant to a technically defective warrant supported by
probable cause also might encourage officers to scrutinize more
closely the form of the warrant, and to point out suspected
judicial errors. We find such arguments speculative, and conclude
that suppression of evidence obtained pursuant to a warrant should
be ordered only on a case-by-case basis, and only in those unusual
cases in which exclusion will further the purposes of the
exclusionary rule. [ Footnote
19 ]

															We have frequently questioned whether the exclusionary rule can
have any deterrent effect when the offending officers acted in the
objectively reasonable belief that their conduct did not violate
the Fourth Amendment.

															"No empirical researcher, proponent or opponent of the rule has
yet been able to establish with any assurance whether the rule has
a deterrent effect. . . ." United States v. Janis, 428 U.S. at 428 U. S. 452 ,
n. 22. But even assuming that the rule effectively Page 468 U. S. 919 deters some police misconduct and provides incentives for the
law enforcement profession as a whole to conduct itself in accord
with the Fourth Amendment, it cannot be expected, and should not be
applied, to deter objectively reasonable law enforcement
activity.

															As we observed in Michigan v. Tucker, 417 U.
S. 433 , 417 U. S. 447 (1974), and reiterated in United States v. Peltier, 422
U.S. at 422 U. S.
539 :

															"The deterrent purpose of the exclusionary rule necessarily
assumes that the police have engaged in willful, or at the very
least negligent, conduct which has deprived the defendant of some
right. By refusing to admit evidence gained as a result of such
conduct, the courts hope to instill in those particular
investigating officers, or in their future counterparts, a greater
degree of care toward the rights of an accused. Where the official
action was pursued in complete good faith, however, the deterrence
rationale loses much of its force."

															The Peltier Court continued, id. at 422 U. S.
542 :

															"If the purpose of the exclusionary rule is to deter unlawful
police conduct, then evidence obtained from a search should be
suppressed only if it can be said that the law enforcement officer
had knowledge, or may properly be charged with knowledge, that the
search was unconstitutional under the Fourth Amendment." See also Illinois v. Gates, 462 U.S. at 462 U. S.
260 -261 (WHITE, J., concurring in judgment); United
States v. Janis, supra, at 428 U. S. 459 ; Brown v. Illinois, 422 U.S. at 422 U. S.
610 -611 (POWELL, J., concurring in part). [ Footnote 20 ] In short, where the
officer's conduct is objectively reasonable, Page 468 U. S. 920 "excluding the evidence will not further the ends of the
exclusionary rule in any appreciable way; for it is painfully
apparent that . . . the officer is acting as a reasonable officer
would and should act in similar circumstances. Excluding the
evidence can in no way affect his future conduct unless it is to
make him less willing to do his duty." Stone v. Powell, 428 U.S. at 428 U. S.
539 -540 (WHITE, J., dissenting).

															This is particularly true, we believe, when an officer, acting
with objective good faith, has obtained a search warrant from a
judge or magistrate and acted within its scope. [ Footnote 21 ] In most Page 468 U. S. 921 such cases, there is no police illegality, and thus nothing to
deter. It is the magistrate's responsibility to determine whether
the officer's allegations establish probable cause and, if so, to
issue a warrant comporting in form with the requirements of the
Fourth Amendment. In the ordinary case, an officer cannot be
expected to question the magistrate's probable cause determination
or his judgment that the form of the warrant is technically
sufficient. "[O]nce the warrant issues, there is literally nothing
more the policeman can do in seeking to comply with the law." Id. at 428 U. S. 498 (BURGER, C.J., concurring). Penalizing the officer for the
magistrate's error, rather than his own, cannot logically
contribute to the deterrence of Fourth Amendment violations.
[ Footnote 22 ] Page 468 U. S. 922 C We conclude that the marginal or nonexistent benefits produced
by suppressing evidence obtained in objectively reasonable reliance
on a subsequently invalidated search warrant cannot justify the
substantial costs of exclusion. We do not suggest, however, that
exclusion is always inappropriate in cases where an officer has
obtained a warrant and abided by its terms. "[S]earches pursuant to
a warrant will rarely require any deep inquiry into
reasonableness," Illinois v. Gates, 462 U.S. at 462 U. S. 267 (WHITE, J., concurring in judgment), for "a warrant issued by a
magistrate normally suffices to establish" that a law enforcement
officer has "acted in good faith in conducting the search." United States v. Ross, 456 U. S. 798 , 456 U. S. 823 ,
n. 32 (1982). Nevertheless, the officer's reliance on the
magistrate's probable cause determination and on the technical
sufficiency of the warrant he issues must be objectively
reasonable, cf. Harlow v. Fitzgerald, 457 U.
S. 800 , 457 U. S.
815 -819 (1982), [ Footnote 23 ] and it is clear that, in some
circumstances Page 468 U. S. 923 the officer [ Footnote 24 ]
will have no reasonable grounds for believing that the warrant was
properly issued.

															Suppression therefore remains an appropriate remedy if the
magistrate or judge in issuing a warrant was misled by information
in an affidavit that the affiant knew was false or would have known
was false except for his reckless disregard of the truth. Franks v. Delaware, 438 U. S. 154 (1978). The exception we recognize today will also not apply in
cases where the issuing magistrate wholly abandoned his judicial
role in the manner condemned in Lo-Ji Sales, Inc. v. New
York, 442 U. S. 319 (1979); in such circumstances, no reasonably well-trained officer
should rely on the warrant. Nor would an officer manifest objective
good faith in relying on a warrant based on an affidavit "so
lacking in indicia of probable cause as to render official belief
in its existence entirely unreasonable." Brown v.
Illinois, 422 U.S. at 422 U. S. 610 -611 (POWELL, J., concurring in part); see Illinois v. Gates, supra, at 462 U. S.
263 -264 (WHITE, J., concurring in judgment). Finally,
depending on the circumstances of the particular case, a warrant
may be so facially deficient -- i.e., in failing to
particularize the place to be searched or the things to be seized
-- that the executing officers cannot reasonably presume it to be
valid. Cf. Massachusetts v. Sheppard, post at 468 U. S.
988 -991.

															In so limiting the suppression remedy, we leave untouched the
probable cause standard and the various requirements for a valid
warrant. Other objections to the modification of Page 468 U. S. 924 the Fourth Amendment exclusionary rule we consider to be
insubstantial. The good faith exception for searches conducted
pursuant to warrants is not intended to signal our unwillingness
strictly to enforce the requirements of the Fourth Amendment, and
we do not believe that it will have this effect. As we have already
suggested, the good faith exception, turning as it does on
objective reasonableness, should not be difficult to apply in
practice. When officers have acted pursuant to a warrant, the
prosecution should ordinarily be able to establish objective good
faith without a substantial expenditure of judicial time.

															Nor are we persuaded that application of a good faith exception
to searches conducted pursuant to warrants will preclude review of
the constitutionality of the search or seizure, deny needed
guidance from the courts, or freeze Fourth Amendment law in its
present state. [ Footnote 25 ]
There is no need for courts to adopt the inflexible practice of
always deciding whether the officers' conduct manifested objective
good faith before turning to the question whether the Fourth
Amendment has been violated. Defendants seeking suppression of the
fruits of allegedly unconstitutional searches or seizures
undoubtedly raise live controversies which Art. III empowers
federal courts to adjudicate. As cases addressing questions of good
faith immunity under 42 U.S.C. § 1983, compare O'Connor v.
Donaldson, 422 U. S. 563 (1975), with Procunier v. Navarette, 434 U.
S. 555 , 434 U. S. 566 ,
n. 14 (1978), and cases involving the harmless error doctrine, compare Milton v. Wainwright, 407 U.
S. 371 , 407 U. S. 372 (1972), with Coleman v. Alabama, 399 U. S.
1 (1970), make clear, courts have considerable Page 468 U. S. 925 discretion in conforming their decisionmaking processes to the
exigencies of particular cases.

															If the resolution of a particular Fourth Amendment question is
necessary to guide future action by law enforcement officers and
magistrates, nothing will prevent reviewing courts from deciding
that question before turning to the good faith issue. [ Footnote 26 ] Indeed, it frequently
will be difficult to determine whether the officers acted
reasonably without resolving the Fourth Amendment issue. Even if
the Fourth Amendment question is not one of broad import, reviewing
courts could decide in particular cases that magistrates under
their supervision need to be informed of their errors, and so
evaluate the officers' good faith only after finding a violation.
In other circumstances, those courts could reject suppression
motions posing no important Fourth Amendment questions by turning
immediately to a consideration of the officers' good faith. We have
no reason to believe that our Fourth Amendment jurisprudence would
suffer by allowing reviewing courts to exercise an informed
discretion in making this choice. IV When the principles we have enunciated today are applied to the
facts of this case, it is apparent that the judgment of the Court
of Appeals cannot stand. The Court of Appeals applied the
prevailing legal standards to Officer Rombach's warrant
application, and concluded that the application could not support
the magistrate's probable cause determination. In so doing, the
court clearly informed the magistrate that he Page 468 U. S. 926 had erred in issuing the challenged warrant. This aspect of the
court's judgment is not under attack in this proceeding.

															Having determined that the warrant should not have issued, the
Court of Appeals understandably declined to adopt a modification of
the Fourth Amendment exclusionary rule that this Court had not
previously sanctioned. Although the modification finds strong
support in our previous cases, the Court of Appeals' commendable
self-restraint is not to be criticized. We have now reexamined the
purposes of the exclusionary rule and the propriety of its
application in cases where officers have relied on a subsequently
invalidated search warrant. Our conclusion is that the rule's
purposes will only rarely be served by applying it in such
circumstances.

															In the absence of an allegation that the magistrate abandoned
his detached and neutral role, suppression is appropriate only if
the officers were dishonest or reckless in preparing their
affidavit or could not have harbored an objectively reasonable
belief in the existence of probable cause. Only respondent Leon has
contended that no reasonably well trained police officer could have
believed that there existed probable cause to search his house;
significantly, the other respondents advance no comparable
argument. Officer Rombach's application for a warrant clearly was
supported by much more than a "bare bones" affidavit. The affidavit
related the results of an extensive investigation and, as the
opinions of the divided panel of the Court of Appeals make clear,
provided evidence sufficient to create disagreement among
thoughtful and competent judges as to the existence of probable
cause. Under these circumstances, the officers' reliance on the
magistrate's determination of probable cause was objectively
reasonable, and application of the extreme sanction of exclusion is
inappropriate.

															Accordingly, the judgment of the Court of Appeals is Reversed. Page 468 U. S. 927 [ Footnote 1 ]

															Respondent Leon moved to suppress the evidence found on his
person at the time of his arrest and the evidence seized from his
residence at 716 South Sunset Canyon. Respondent Stewart's motion
covered the fruits of searches of her residence at 620 Price Drive
and the condominium at 7902 Via Magdalena and statements she made
during the search of her residence. Respondent Sanchez sought to
suppress the evidence discovered during the search of his residence
at 620 Price Drive and statements he made shortly thereafter. He
also joined Stewart's motion to suppress evidence seized from the
condominium. Respondent Del Castillo apparently sought to suppress
all of the evidence seized in the searches. App. 78-80. The
respondents also moved to suppress evidence seized in the searches
of their automobiles.

															[ Footnote 2 ]

															"I just cannot find this warrant sufficient for a showing of
probable cause."

															" * * * *" "There is no question of the reliability and credibility of the
informant as not being established."

															"Some details given tended to corroborate, maybe, the
reliability of [the informant's] information about the previous
transaction, but if it is not a stale transaction, it comes awfully
close to it; and all the other material I think is as consistent
with innocence as it is with guilt."

															" * * * *" "So I just do not think this affidavit can withstand the test. I
find, then, that there is no probable cause in this case for the
issuance of the search warrant. . . ." Id. at 127.

															[ Footnote 3 ]

															The District Court concluded that Sanchez and Stewart had
standing to challenge the search of 620 Price Drive; that Leon had
standing to contest the legality of the search of 716 South Sunset
Canyon; that none of the respondents had established a legitimate
expectation of privacy in the condominium at 7902 Via Magdalena;
and that Stewart and Del Castillo each had standing to challenge
the searches of their automobiles. The Government indicated that it
did not intend to introduce evidence seized from the other
respondents' vehicles. Id. at 127-129. Finally, the court
suppressed statements given by Sanchez and Stewart. Id. at
129-130.

															[ Footnote 4 ]

															"On the issue of good faith, obviously that is not the law of
the Circuit, and I am not going to apply that law."

															"I will say certainly in my view, there is not any question
about good faith. [Officer Rombach] went to a Superior Court judge
and got a warrant; obviously laid a meticulous trail. Had
surveilled for a long period of time, and I believe his testimony
-- and I think he said he consulted with three Deputy District
Attorneys before proceeding himself, and I certainly have no doubt
about the fact that that is true." Id. at 140.

															[ Footnote 5 ]

															In Illinois v. Gates, 462 U. S. 213 (1983), decided last Term, the Court abandoned the two-pronged Aguilar-Spinelli test for determining whether an
informant's tip suffices to establish probable cause for the
issuance of a warrant and substituted in its place a "totality of
the circumstances" approach.

															[ Footnote 6 ]

															Researchers have only recently begun to study extensively the
effects of the exclusionary rule on the disposition of felony
arrests. One study suggests that the rule results in the
nonprosecution or nonconviction of between 0.6% and 2.35% of
individuals arrested for felonies. Davies, A Hard Look at What We
Know (and Still Need to Learn) About the "Costs" of the
Exclusionary Rule: The NU Study and Other Studies of "Lost"
Arrests, 1983 A.B.F.Res.J. 611, 621. The estimates are higher for
particular crimes the prosecution of which depends heavily on
physical evidence. Thus, the cumulative loss due to nonprosecution
or nonconviction of individuals arrested on felony drug charges is
probably in the range of 2.8% to 7.1%. Id. at 680. Davies'
analysis of California data suggests that screening by police and
prosecutors results in the release because of illegal searches or
seizures of as many as 1.4% of all felony arrestees, id. at 650, that 0.9% of felony arrestees are released, because of
illegal searches or seizures, at the preliminary hearing or after
trial, id. at 653, and that roughly 0.05% of all felony
arrestees benefit from reversals on appeal because of illegal
searches. Id. at 654. See also K. Brosi, A
Cross-City Comparison of Felony Case Processing 16, 18-19 (1979);
U.S. General Accounting Office, Report of the Comptroller General
of the United States, Impact of the Exclusionary Rule on Federal
Criminal Prosecutions 10-11, 14 (1979); F. Feeney, F. Dill, &
A. Weir, Arrests Without Convictions: How Often They Occur and Why
203-206 (National Institute of Justice 1983); National Institute of
Justice, The Effects of the Exclusionary Rule: A Study in
California 1-2 (1982); Nardulli, The Societal Cost of the
Exclusionary Rule: An Empirical Assessment, 1983 A.B.F.Res.J. 585,
600. The exclusionary rule also has been found to affect the
plea-bargaining process. S. Schlesinger, Exclusionary Injustice:
The Problem of Illegally Obtained Evidence 63 (1977). But
see Davies, supra, at 668-669; Nardulli, supra, at 604-606.

															Many of these researchers have concluded that the impact of the
exclusionary rule is insubstantial, but the small percentages with
which they deal mask a large absolute number of felons who are
released because the cases against them were based in part on
illegal searches or seizures.

															"[A]ny rule of evidence that denies the jury access to clearly
probative and reliable evidence must bear a heavy burden of
justification, and must be carefully limited to the circumstances
in which it will pay its way by deterring official
unlawlessness." Illinois v. Gates, 462 U.S. at 462 U. S.
257 -258 (WHITE, J., concurring in judgment). Because we
find that the rule can have no substantial deterrent effect in the
sorts of situations under consideration in this case, see
infra at 468 U. S.
916 -921, we conclude that it cannot pay its way in those
situations.

															[ Footnote 7 ]

															"Brown's focus on 'the causal connection between the illegality
and the confession' reflected the two policies behind the use of
the exclusionary rule to effectuate the Fourth Amendment. Where
there is a close causal connection between the illegal seizure and
the confession, not only is exclusion of the evidence more likely
to deter similar police misconduct in the future, but use of the
evidence is more likely to compromise the integrity of the
courts." Dunaway v. New York, 442 U.S. at 442 U. S.
217 -218 (citation omitted).

															[ Footnote 8 ]

															We have held, however, that the exclusionary rule requires
suppression of evidence obtained in searches carried out pursuant
to statutes, not yet declared unconstitutional, purporting to
authorize searches and seizures without probable cause or search
warrants. See, e.g., Ybarra v. Illinois, 444 U. S.
85 (1979); Torres v. Puerto Rico, 442 U.
S. 465 (1979); Almeida-Sanchez v. United
States, 413 U. S. 266 (1973); Sibron v. New York, 392 U. S.
40 (1968); Berger v. New York, 388 U. S.
41 (1967).

															"Those decisions involved statutes which, by their own terms,
authorized searches under circumstances which did not satisfy the
traditional warrant and probable cause requirements of the Fourth
Amendment." Michigan v. DeFillippo, 443 U.S. at 443 U. S. 39 .
The substantive Fourth Amendment principles announced in those
cases are fully consistent with our holding here.

															[ Footnote 9 ]

															The Court held in United States v. Johnson that a
construction of the Fourth Amendment that did not constitute a
"clear break with the past" is to be applied to all convictions not
yet final when the decision was handed down. The limited holding, see 457 U.S. at 457 U. S. 562 ,
turned in part on the Court's judgment that

															"[f]ailure to accord any retroactive effect to Fourth
Amendment rulings would 'encourage police or other courts to
disregard the plain purport of our decisions and to adopt a
let's-wait-until-it's-decided approach.'" Id. at 457 U. S. 561 (emphasis in original) (quoting Desist v. United States, 394 U. S. 244 , 394 U. S. 277 (1969) (Fortas, J., dissenting)). Contrary to respondents'
assertions, nothing in Johnson precludes adoption of a
good faith exception tailored to situations in which the police
have reasonably relied on a warrant issued by a detached and
neutral magistrate, but later found to be defective.

															[ Footnote 10 ]

															Our retroactivity decisions have, for the most part, turned on
our assessments of

															"(a) the purpose to be served by the new standards, (b) the
extent of the reliance by law enforcement authorities on the old
standards, and (c) the effect on the administration of justice of a
retroactive application of the new standards." Stovall v. Denno, 388 U. S. 293 , 388 U. S. 297 (1967). As we observed earlier this Term:

															"In considering the reliance factor, this Court's cases have
looked primarily to whether law enforcement authorities and state
courts have justifiably relied on a prior rule of law said to be
different from that announced by the decision whose retroactivity
is at issue. Unjustified 'reliance' is no bar to retroactivity.
This inquiry is often phrased in terms of whether the new decision
was foreshadowed by earlier cases or was a 'clear break with the
past.'" Solem v. Stumes, 465 U. S. 638 , 465 U. S.
645 -646 (1984).

															[ Footnote 11 ]

															Members of the Court have, however, urged reconsideration of the
scope of the exclusionary rule. See, e.g., Stone v.
Powell, 428 U. S. 465 , 428 U. S. 496 (1976) (BURGER, C.J., concurring); id. at 428 U. S. 536 (WHITE, J., dissenting); Illinois v. Gates, 462 U.S. at 462 U. S.
254 -267 (WHITE, J., concurring in judgment); Brown
v. Illinois, 422 U. S. 590 , 422 U. S.
609 -612 (1975) (POWELL, J., concurring in part); Schneckloth v. Bustamonte, 412 U.
S. 218 , 412 U. S.
261 -271 (1973) (POWELL, J., concurring); California
v. Minjares, 443 U. S. 916 (1979) (REHNQUIST, J., dissenting from denial of stay). One Court
of Appeals, no doubt influenced by these individual urgings, has
adopted a form of good faith exception to the exclusionary rule. United States v. Williams, 622 F.2d 830 (CA5 1980) (en
banc), cert. denied, 449 U.S. 1127 (1981).

															[ Footnote 12 ]

															Indeed,

															"it would be an unthinkable imposition upon [the magistrate's]
authority if a warrant affidavit, revealed after the fact to
contain a deliberately or recklessly false statement, were to stand
beyond impeachment."

															438 U.S. at 438 U. S.
165 .

															[ Footnote 13 ] See also Beck v. Ohio, 379 U. S.
89 (1964), in which the Court concluded that

															"the record . . . does not contain a single objective fact to
support a belief by the officers that the petitioner was engaged in
criminal activity at the time they arrested him." Id. at 379 U. S. 95 .
Although the Court was willing to assume that the arresting
officers acted in good faith, it concluded:

															"'[G]ood faith on the part of the arresting officers is not
enough.' Henry v. United States, 361 U. S.
98 , 361 U. S. 102 . If subjective
good faith alone were the test, the protections of the Fourth
Amendment would evaporate, and the people would be 'secure in their
persons, houses, papers, and effects,' only in the discretion of
the police." Id. at 379 U. S. 97 . We
adhere to this view and emphasize that nothing in this opinion is
intended to suggest a lowering of the probable cause standard. On
the contrary, we deal here only with the remedy to be applied to a
concededly unconstitutional search.

															[ Footnote 14 ]

															Although there are assertions that some magistrates become
rubber stamps for the police, and others may be unable effectively
to screen police conduct, see, e.g., 2 W. LaFave, Search
and Seizure § 4.1 (1978); Kamisar, Does (Did) (Should) The
Exclusionary Rule Rest on a "Principled Basis" Rather than an
"Empirical Proposition"?, 16 Creighton L.Rev. 565, 569-571 (1983);
Schroeder, Deterring Fourth Amendment Violations: Alternatives to
the Exclusionary Rule, 69 Geo.L.J. 1361, 1412 (1981), we are not
convinced that this is a problem of major proportions. See L. Tiffany, D. McIntyre, & D. Rotenberg, Detection of Crime 119
(1967); Israel, Criminal Procedure, the Burger Court, and the
Legacy of the Warren Court, 75 Mich.L.Rev. 1319, 1414, n. 396
(1977); P. Johnson, New Approaches to Enforcing the Fourth
Amendment 8-10 (Working Paper, Sept.1978), quoted in Y. Kamisar, W.
LaFave, & J. Israel, Modern Criminal Procedure 229-230 (5th
ed.1980); R. Van Duizend, L. Sutton, & C. Carter, The Search
Warrant Process, ch. 7 (Review Draft, National Center for State
Courts, 1983).

															[ Footnote 15 ]

															As the Supreme Judicial Court of Massachusetts recognized in Commonwealth v. Sheppard, 387 Mass. 488, 506, 441
N.E.2d 725 735 (1982):

															"The exclusionary rule may not be well tailored to deterring
judicial misconduct. If applied to judicial misconduct, the rule
would be just as costly as it is when it is applied to police
misconduct, but it may be ill-fitted to the job-created motivations
of judges. . . . [I]deally, a judge is impartial as to whether a
particular piece of evidence is admitted or a particular defendant
convicted. Hence, in the abstract, suppression of a particular
piece of evidence may not be as effective a disincentive to a
neutral judge as it would be to the police. It may be that a ruling
by an appellate court that a search warrant was unconstitutional
would be sufficient to deter similar conduct in the future by
magistrates." But see United States v. Karathanos, 531 F.2d 26, 33-34
(CA2), cert. denied, 428 U.S. 910 (1976).

															[ Footnote 16 ] See, e.g., Stone v. Powell, 428 U.S. at 428 U. S. 498 (BURGER, C.J., concurring); Oaks, Studying the Exclusionary Rule in
Search and Seizure, 37 U.Chi.L.Rev. 665, 709-710 (1970).

															[ Footnote 17 ] See, e.g., Dunaway v. New York, 442 U.
S. 200 , 442 U. S. 221 (1979) (STEVENS, J., concurring); Mertens & Wasserstrom, The
Good Faith Exception to the Exclusionary Rule: Deregulating the
Police and Derailing the Law, 70 Geo. L.J. 365, 399-401 (1981).

															[ Footnote 18 ]

															Limiting the application of the exclusionary sanction may well
increase the care with which magistrates scrutinize warrant
applications. We doubt that magistrates are more desirous of
avoiding the exclusion of evidence obtained pursuant to warrants
they have issued than of avoiding invasions of privacy.

															Federal magistrates, moreover, are subject to the direct
supervision of district courts. They may be removed for
"incompetency, misconduct, neglect of duty, or physical or mental
disability." 28 U.S.C. § 631(i). If a magistrate serves merely as a
"rubber stamp" for the police or is unable to exercise mature
judgment, closer supervision or removal provides a more effective
remedy than the exclusionary rule.

															[ Footnote 19 ]

															Our discussion of the deterrent effect of excluding evidence
obtained in reasonable reliance on a subsequently invalidated
warrant assumes, of course, that the officers properly executed the
warrant and searched only those places and for those objects that
it was reasonable to believe were covered by the warrant. Cf.
Massachusetts v. Sheppard, post at 468 U. S. 989 ,
n. 6 ("[I]t was not unreasonable for the police in this case to
rely on the judge's assurances that the warrant authorized the
search they had requested").

															[ Footnote 20 ]

															We emphasize that the standard of reasonableness we adopt is an
objective one. Many objections to a good faith exception assume
that the exception will turn on the subjective good faith of
individual officers.

															"Grounding the modification in objective reasonableness,
however, retains the value of the exclusionary rule as an incentive
for the law enforcement profession as a whole to conduct themselves
in accord with the Fourth Amendment." Illinois v. Gates, 462 U.S. at 462 U. S. 261 ,
n. 15 (WHITE, J., concurring in judgment); see Dunaway v. New
York, 442 U.S. at 442 U. S. 221 (STEVENS, J., concurring). The objective standard we adopt,
moreover, requires officers to have a reasonable knowledge of what
the law prohibits. United States v. Peltier, 422 U.
S. 531 , 422 U. S. 542 (1975). As Professor Jerold Israel has observed:

															"The key to the [exclusionary] rule's effectiveness as a
deterrent lies, I believe, in the impetus it has provided to police
training programs that make officers aware of the limits imposed by
the fourth amendment and emphasize the need to operate within those
limits. [An objective good faith exception] is not likely to result
in the elimination of such programs, which are now viewed as an
important aspect of police professionalism. Neither is it likely to
alter the tenor of those programs; the possibility that illegally
obtained evidence may be admitted in borderline cases is unlikely
to encourage police instructors to pay less attention to fourth
amendment limitations. Finally, [it] should not encourage officers
to pay less attention to what they are taught, as the requirement
that the officer act in 'good faith' is inconsistent with closing
one's mind to the possibility of illegality."

															Israel, supra, n. 14, at 1412-1413 (footnotes
omitted).

															[ Footnote 21 ]

															According to the Attorney General's Task Force on Violent Crime,
Final Report (1981), the situation in which an officer relies on a
duly authorized warrant

															"is a particularly compelling example of good faith. A warrant
is a judicial mandate to an officer to conduct a search or make an
arrest, and the officer has a sworn duty to carry out its
provisions. Accordingly, we believe that there should be a rule
which states that evidence obtained pursuant to and within the
scope of a warrant is prima facie the result of good faith
on the part of the officer seizing the evidence." Id. at 55.

															[ Footnote 22 ]

															To the extent that JUSTICE STEVENS' conclusions concerning the
integrity of the courts, post at 468 U. S.
976 -978, rest on a foundation other than his judgment,
which we reject, concerning the effects of our decision on the
deterrence of police illegality, we find his argument
unpersuasive.

															"Judicial integrity clearly does not mean that the courts must
never admit evidence obtained in violation of the Fourth
Amendment." United States v. Janis, 428 U.
S. 433 , 428 U. S. 458 ,
n. 35 (1976).

															"While courts, of course, must ever be concerned with preserving
the integrity of the judicial process, this concern has limited
force as a justification for the exclusion of highly probative
evidence." Stone v. Powell, 428 U.S. at 428 U. S. 485 .
Our cases establish that the question whether the use of illegally
obtained evidence in judicial proceedings represents judicial
participation in a Fourth Amendment violation and offends the
integrity of the courts

															"is essentially the same as the inquiry into whether exclusion
would serve a deterrent purpose. . . . The analysis showing that
exclusion in this case has no demonstrated deterrent effect and is
unlikely to have any significant such effect shows, by the same
reasoning, that the admission of the evidence is unlikely to
encourage violations of the Fourth Amendment." United States v. Janis, supra, at 428 U. S. 459 ,
n. 35. Absent unusual circumstances, when a Fourth Amendment
violation has occurred because the police have reasonably relied on
a warrant issued by a detached and neutral magistrate but
ultimately found to be defective, "the integrity of the courts is
not implicated." Illinois v. Gates, supra, at 462 U. S. 259 ,
n. 14 (WHITE, J., concurring in judgment). See Stone v.
Powell, 428 U.S. at 428 U. S. 485 ,
n. 23; id. at 428 U. S. 540 (WHITE, J., dissenting); United States v. Peltier, 422 U. S. 531 , 422 U. S.
536 -539 (1975).

															[ Footnote 23 ]

															In Harlow, we eliminated the subjective component of
the qualified immunity public officials enjoy in suits seeking
damages for alleged deprivations of constitutional rights. The
situations are not perfectly analogous, but we also eschew
inquiries into the subjective beliefs of law enforcement officers
who seize evidence pursuant to a subsequently invalidated warrant.
Although we have suggested that,

															"[o]n occasion, the motive with which the officer conducts an
illegal search may have some relevance in determining the propriety
of applying the exclusionary rule," Scott v. United States, 436 U.
S. 128 , 436 U. S. 139 ,
n. 13 (1978), we believe that

															"sending state and federal courts on an expedition into the
minds of police officers would produce a grave and fruitless
misallocation of judicial resources." Massachusetts v. Painten, 389 U.
S. 560 , 389 U. S. 565 (1968) (WHITE, J., dissenting). Accordingly, our good faith inquiry
is confined to the objectively ascertainable question whether a
reasonably well trained officer would have known that the search
was illegal despite the magistrate's authorization. In making this
determination, all of the circumstances -- including whether the
warrant application had previously been rejected by a different
magistrate -- may be considered.

															[ Footnote 24 ]

															References to "officer" throughout this opinion should not be
read too narrowly. It is necessary to consider the objective
reasonableness not only of the officers who eventually executed a
warrant, but also of the officers who originally obtained it or who
provided information material to the probable cause determination.
Nothing in our opinion suggests, for example, that an officer could
obtain a warrant on the basis of a "bare bones" affidavit and then
rely on colleagues who are ignorant of the circumstances under
which the warrant was obtained to conduct the search. See
Whiteley v. Walden, 401 U. S. 560 , 401 U. S. 568 (191).

															[ Footnote 25 ]

															The argument that defendants will lose their incentive to
litigate meritorious Fourth Amendment claims as a result of the
good faith exception we adopt today is unpersuasive. Although the
exception might discourage presentation of insubstantial
suppression motions, the magnitude of the benefit conferred on
defendants by a successful motion makes it unlikely that litigation
of colorable claims will be substantially diminished.

															[ Footnote 26 ]

															It has been suggested, in fact, that

															"the recognition of a 'penumbral zone,' within which an
inadvertent mistake would not call for exclusion, . . . will make
it less tempting for judges to bend fourth amendment standards to
avoid releasing a possibly dangerous criminal because of a minor
and unintentional miscalculation by the police."

															Schroeder, supra, n. 14, at 1420-1421 (footnote
omitted); see Ashdown, Good Faith, the Exclusionary
Remedy, and Rule-Oriented Adjudication in the Criminal Process, 24
Wm. & Mary L.Rev. 335, 383-384 (1983).

															JUSTICE BLACKMUN, concurring.

															The Court today holds that evidence obtained in violation of the
Fourth Amendment by officers acting in objectively reasonable
reliance on a search warrant issued by a neutral and detached
magistrate need not be excluded, as a matter of federal law, from
the case in chief of federal and state criminal prosecutions. In so
doing, the Court writes another chapter in the volume of Fourth
Amendment law opened by Weeks v. United States, 232 U. S. 383 (1914). I join the Court's opinion in this case and the one in Massachusetts v. Sheppard, post, p. 468 U. S. 981 ,
because I believe that the rule announced today advances the
legitimate interests of the criminal justice system without
sacrificing the individual rights protected by the Fourth
Amendment. I write separately, however, to underscore what I regard
as the unavoidably provisional nature of today's decisions.

															As the Court's opinion in this case makes clear, the Court has
narrowed the scope of the exclusionary rule because of an empirical
judgment that the rule has little appreciable effect in cases where
officers act in objectively reasonable reliance on search warrants. See ante at 468 U. S.
918 -921. Because I share the view that the exclusionary
rule is not a constitutionally compelled corollary of the Fourth
Amendment itself, see ante at 468 U. S.
905 -906, I see no way to avoid making an empirical
judgment of this sort, and I am satisfied that the Court has made
the correct one on the information before it. Like all courts, we
face institutional limitations on our ability to gather information
about "legislative facts," and the exclusionary rule itself has
exacerbated the shortage of hard data concerning the behavior of
police officers in the absence of such a rule. See United
States v. Janis, 428 U. S. 433 , 428 U. S.
448 -453 (1976). Nonetheless, we cannot escape the
responsibility to decide the question before us, however imperfect
our information may be, and I am prepared to join the Court on the
information now at hand. Page 468 U. S. 928 What must be stressed, however, is that any empirical judgment
about the effect of the exclusionary rule in a particular class of
cases necessarily is a provisional one. By their very nature, the
assumptions on which we proceed today cannot be cast in stone. To
the contrary, they now will be tested in the real world of state
and federal law enforcement, and this Court will attend to the
results. If it should emerge from experience that, contrary to our
expectations, the good faith exception to the exclusionary rule
results in a material change in police compliance with the Fourth
Amendment, we shall have to reconsider what we have undertaken
here. The logic of a decision that rests on untested predictions
about police conduct demands no less.

															If a single principle may be drawn from this Court's
exclusionary rule decisions, from Weeks through Mapp
v. Ohio, 367 U. S. 643 (1961), to the decisions handed down today, it is that the scope of
the exclusionary rule is subject to change in light of changing
judicial understanding about the effects of the rule outside the
confines of the courtroom. It is incumbent on the Nation's law
enforcement officers, who must continue to observe the Fourth
Amendment in the wake of today's decisions, to recognize the
double-edged nature of that principle.

															JUSTICE BRENNAN, with whom JUSTICE MARSHALL joins, dissenting. * Ten years ago, in United States v. Calandra, 414 U. S. 338 (1974), I expressed the fear that the Court's decision

															"may signal that a majority of my colleagues have positioned
themselves to reopen the door [to evidence secured by official
lawlessness] still further and abandon altogether the exclusionary
rule in search and seizure cases." Id. at 414 U. S. 365 (dissenting opinion). Since then, in case after case, I have
witnessed the Court's gradual but determined strangulation Page 468 U. S. 929 of the rule. [ Footnote 2/1 ] It
now appears that the Court's victory over the Fourth Amendment is
complete. That today's decisions represent the piece de
resistance of the Court's past efforts cannot be doubted, for
today the Court sanctions the use in the prosecution's case in
chief of illegally obtained evidence against the individual whose
rights have been violated -- a result that had previously been
thought to be foreclosed.

															The Court seeks to justify this result on the ground that the
"costs" of adhering to the exclusionary rule in cases like those
before us exceed the "benefits." But the language of deterrence and
of cost/benefit analysis, if used indiscriminately, can have a
narcotic effect. It creates an illusion of technical precision and
ineluctability. It suggests that not only constitutional principle
but also empirical data support the majority's result. When the
Court's analysis is examined carefully, however, it is clear that
we have not been treated to an honest assessment of the merits of
the exclusionary rule, but have instead been drawn into a curious
world where the "costs" of excluding illegally obtained evidence
loom to exaggerated heights, and where the "benefits" of such
exclusion are made to disappear with a mere wave of the hand.

															The majority ignores the fundamental constitutional importance
of what is at stake here. While the machinery of law enforcement,
and indeed the nature of crime itself, have changed dramatically
since the Fourth Amendment became part of the Nation's fundamental
law in 1791, what the Framers understood then remains true today --
that the task of combating crime and convicting the guilty will in
every era seem of such critical and pressing concern that we may be
lured by the temptations of expediency into forsaking our Page 468 U. S. 930 commitment to protecting individual liberty and privacy. It was
for that very reason that the Framers of the Bill of Rights
insisted that law enforcement efforts be permanently and
unambiguously restricted in order to preserve personal freedoms. In
the constitutional scheme they ordained, the sometimes unpopular
task of ensuring that the government's enforcement efforts remain
within the strict boundaries fixed by the Fourth Amendment was
entrusted to the courts. As James Madison predicted in his address
to the First Congress on June 8, 1789:

															"If [these rights] are incorporated into the Constitution,
independent tribunals of justice will consider themselves in a
peculiar manner the guardians of those rights; they will be an
impenetrable bulwark against every assumption of power in the
Legislative or Executive; they will be naturally led to resist
every encroachment upon rights expressly stipulated for in the
Constitution by the declaration of rights."

															1 Annals of Cong. 439. If those independent tribunals lose their
resolve, however, as the Court has done today, and give way to the
seductive call of expediency, the vital guarantees of the Fourth
Amendment are reduced to nothing more than a "form of words." Silverthorne Lumber Co. v. United States, 251 U.
S. 385 , 251 U. S. 392 (1920).

															A proper understanding of the broad purposes sought to be served
by the Fourth Amendment demonstrates that the principles embodied
in the exclusionary rule rest upon a far firmer constitutional
foundation than the shifting sands of the Court's deterrence
rationale. But even if I were to accept the Court's chosen method
of analyzing the question posed by these cases, I would still
conclude that the Court's decision cannot be justified. I The Court holds that physical evidence seized by police officers
reasonably relying upon a warrant issued by a detached Page 468 U. S. 931 and neutral magistrate is admissible in the prosecution's case
in chief, even though a reviewing court has subsequently determined
either that the warrant was defective, No. 82-963, or that those
officers failed to demonstrate when applying for the warrant that
there was probable cause to conduct the search, No. 82-1771. I have
no doubt that these decisions will prove in time to have been a
grave mistake. But, as troubling and important as today's new
doctrine may be for the administration of criminal justice in this
country, the mode of analysis used to generate that doctrine also
requires critical examination, for it may prove in the long run to
pose the greater threat to our civil liberties. A At bottom, the Court's decision turns on the proposition that
the exclusionary rule is merely a

															"'judicially created remedy designed to safeguard Fourth
Amendment rights generally through its deterrent effect, rather
than a personal constitutional right.'" Ante at 468 U.S.
906 , quoting United States v. Calandra, 414 U.S. at 414 U. S. 348 .
The germ of that idea is found in Wolf v. Colorado, 338 U. S. 25 (1949), and although I had thought that such a narrow conception of
the rule had been forever put to rest by our decision in Mapp
v. Ohio, 367 U. S. 643 (1961), it has been revived by the present Court and reaches full
flower with today's decision. The essence of this view, as
expressed initially in the Calandra opinion and as
reiterated today, is that the sole

															"purpose of the Fourth Amendment is to prevent unreasonable
governmental intrusions into the privacy of one's person, house,
papers, or effects. The wrong condemned is the unjustified
governmental invasion of these areas of an individual's life. That
wrong . . . is fully accomplished by the original search
without probable cause."

															414 U.S. at 414 U. S. 354 (emphasis added); see also ante at 468 U.S. 906 . This reading of the
Amendment implies that its proscriptions are directed solely at
those government agents who may actually invade an individual's
constitutionally Page 468 U. S. 932 protected privacy. The courts are not subject to any direct
constitutional duty to exclude illegally obtained evidence, because
the question of the admissibility of such evidence is not addressed
by the Amendment. This view of the scope of the Amendment relegates
the judiciary to the periphery. Because the only constitutionally
cognizable injury has already been "fully accomplished" by the
police by the time a case comes before the courts, the Constitution
is not itself violated if the judge decides to admit the tainted
evidence. Indeed, the most the judge can do is wring his hands and
hope that perhaps, by excluding such evidence, he can deter future
transgressions by the police.

															Such a reading appears plausible, because, as critics of the
exclusionary rule never tire of repeating, [ Footnote 2/2 ] the Fourth Amendment makes no express
provision for the exclusion of evidence secured in violation of its
commands. A short answer to this claim, of course, is that many of
the Constitution's most vital imperatives are stated in general
terms, and the task of giving meaning to these precepts is
therefore left to subsequent judicial decisionmaking in the context
of concrete cases. The nature of our Constitution, as Chief Justice
Marshall long ago explained,

															"requires that only its great outlines should be marked, its
important objects designated, and the minor ingredients which
compose those objects be deduced from the nature of the objects
themselves." McCulloch v.
Maryland , 4 Wheat. 316, 17 U. S. 407 (1819).

															A more direct answer may be supplied by recognizing that the
Amendment, like other provisions of the Bill of Rights, restrains
the power of the government as a whole; it does not specify only a
particular agency and exempt all others. The judiciary is
responsible, no less than the executive, for ensuring that
constitutional rights are respected. Page 468 U. S. 933 When that fact is kept in mind, the role of the courts and their
possible involvement in the concerns of the Fourth Amendment comes
into sharper focus. Because seizures are executed principally to
secure evidence, and because such evidence generally has utility in
our legal system only in the context of a trial supervised by a
judge, it is apparent that the admission of illegally obtained
evidence implicates the same constitutional concerns as the initial
seizure of that evidence. Indeed, by admitting unlawfully seized
evidence, the judiciary becomes a part of what is, in fact, a
single governmental action prohibited by the terms of the
Amendment. [ Footnote 2/3 ] Once that
connection between the evidence-gathering role of the police and
the evidence-admitting function of the courts is acknowledged, the
plausibility of the Court's interpretation becomes more suspect.
Certainly nothing in the language or history of the Fourth
Amendment suggests that a recognition of this evidentiary link
between the police and the courts was meant to be foreclosed.
[ Footnote 2/4 ] It is difficult to
give any meaning Page 468 U. S. 934 at all to the limitations imposed by the Amendment if they are
read to proscribe only certain conduct by the police, but to allow
other agents of the same government to take advantage of evidence
secured by the police in violation of its requirements. [ Footnote 2/5 ] The Amendment therefore must
be read to condemn not only the initial unconstitutional invasion
of privacy -- which is done, after all, for the purpose of securing
evidence -- but also the subsequent use of any evidence so
obtained. Page 468 U. S. 935 The Court evades this principle by drawing an artificial line
between the constitutional rights and responsibilities that are
engaged by actions of the police and those that are engaged when a
defendant appears before the courts. According to the Court, the
substantive protections of the Fourth Amendment are wholly
exhausted at the moment when police unlawfully invade an
individual's privacy, and thus no substantive force remains to
those protections at the time of trial when the government seeks to
use evidence obtained by the police.

															I submit that such a crabbed reading of the Fourth Amendment
casts aside the teaching of those Justices who first formulated the
exclusionary rule, and rests ultimately on an impoverished
understanding of judicial responsibility in our constitutional
scheme. For my part, "[t]he right of the people to be secure in
their persons, houses, papers, and effects, against unreasonable
searches and seizures" comprises a personal right to exclude all
evidence secured by means of unreasonable searches and seizures.
The right to be free from the initial invasion of privacy and the
right of exclusion are coordinate components of the central
embracing right to be free from unreasonable searches and
seizures.

															Such a conception of the rights secured by the Fourth Amendment
was unquestionably the original basis of what has come to be called
the exclusionary rule when it was first formulated in Weeks v.
United States, 232 U. S. 383 (1914). There the Court considered whether evidence seized in
violation of the Fourth Amendment by a United States Marshal could
be admitted at trial after the defendant had moved that the
evidence be returned. Significantly, although the Court considered
the Marshal's initial invasion of the defendant's home to be
unlawful, it went on to consider a question that

															"involves the right of the court in a criminal prosecution to
retain for the purposes of evidence the letters and correspondence
of the accused, seized in his house in his absence without his
authority, by a United States Marshal holding no Page 468 U. S. 936 warrant for . . . the search of his premises." Id. at 232 U. S. 393 .
In answering that question, Justice Day, speaking for a unanimous
Court, expressly recognized that the commands of the Fourth
Amendment were addressed to both the courts and the Executive
Branch:

															"The effect of the Fourth Amendment is to put the courts of the
United States and Federal officials, in the exercise of their power
and authority, under limitations and restraints as to the exercise
of such power and authority, and to forever secure the people,
their persons, houses, papers and effects against all unreasonable
searches and seizures under the guise of law. This protection
reaches all alike, whether accused of crime or not, and the
duty of giving to it force and effect is obligatory upon all
entrusted under our Federal system with the enforcement of the
laws. The tendency of those who execute the criminal laws of
the country to obtain conviction by means of unlawful seizures . .
. should find no sanction in the judgments of the courts, which are
charged at all times with the support of the Constitution and to
which people of all conditions have a right to appeal for the
maintenance of such fundamental rights." Id. at 232 U. S.
391 -392.

															The heart of the Weeks opinion, and for me the
beginning of wisdom about the Fourth Amendment's proper meaning, is
found in the following passage:

															"If letters and private documents can . . . be seized and held
and used in evidence against a citizen accused of an offense, the
protection of the Fourth Amendment declaring his right to be secure
against such searches and seizures is of no value, and, so far as
those thus placed are concerned, might as well be stricken from the
Constitution. The efforts of the courts and [federal] officials to
bring the guilty to punishment, praiseworthy as they are, are not
to be aided by the sacrifice of those great Page 468 U. S. 937 principles established by years of endeavor and suffering which
have resulted in their embodiment in the fundamental law of the
land. The United States Marshal could only have invaded the house
of the accused when armed with a warrant issued as required by the
Constitution. . . . Instead, he acted without sanction of law,
doubtless prompted by the desire to bring further proof to the aid
of the Government, and, under color of his office, undertook to
make a seizure of private papers in direct violation of the
constitutional prohibition against such action. . . . To sanction
such proceedings would be to affirm by judicial decision a manifest
neglect, if not an open defiance, of the prohibitions of the
Constitution intended for the protection of the people against such
unauthorized action." Id. at 232 U. S.
393 -394.

															What this passage succinctly captures is the essential
recognition, ignored by the present Court, that seizures are
generally executed for the purpose of bringing "proof to the aid of
the Government," id. at 232 U. S. 393 ,
that the utility of such evidence in a criminal prosecution arises
ultimately in the context of the courts, and that the courts
therefore cannot be absolved of responsibility for the means by
which evidence is obtained. As the Court in Weeks clearly
recognized, the obligations cast upon government by the Fourth
Amendment are not confined merely to the police. In the words of
Justice Holmes:

															"If the search and seizure are unlawful as invading personal
rights secured by the Constitution, those rights would be infringed
yet further if the evidence were allowed to be used." Dodge v. United States, 272 U.
S. 530 , 272 U. S. 32 (1926). As the Court further explained in Olmstead v. United
States, 277 U. S. 438 (1928):

															"The striking outcome of the Weeks case and those which
followed it was the sweeping declaration that the Fourth Amendment,
although not referring to or limiting the use of evidence in
courts, really forbade its introduction if obtained by government
officers through a Page 468 U. S. 938 violation of the Amendment. Theretofore, many had supposed,
under the ordinary common law rules, if the tendered evidence was
pertinent, the method of obtaining it was unimportant. . . . But in
the Weeks case and those which followed, this Court
decided with great emphasis, and established as the law for the
federal courts, that the protection of the Fourth Amendment would
be much impaired unless it was held that not only was the official
violator of the rights under the Amendment subject to an action at
the suit of the injured defendant, but also that the evidence
thereby obtained could not be received." Id. at 277 U. S.
462 -463.

															That conception of the rule, in my view, is more faithful to the
meaning and purpose of the Fourth Amendment and to the judiciary's
role as the guardian of the people's constitutional liberties. In
contrast to the present Court's restrictive reading, the Court in Weeks recognized that, if the Amendment is to have any
meaning, police and the courts cannot be regarded as constitutional
strangers to each other; because the evidence-gathering role of the
police is directly linked to the evidence-admitting function of the
courts, an individual's Fourth Amendment rights may be undermined
as completely by one as by the other. B From the foregoing, it is clear why the question whether the
exclusion of evidence would deter future police misconduct was
never considered a relevant concern in the early cases from Weeks to Olmstead. [ Footnote 2/6 ] In those formative decisions, the Court
plainly understood that the exclusion of illegally obtained
evidence was compelled not by judicially fashioned Page 468 U. S. 939 remedial purposes, but rather by a direct constitutional
command. A new phase in the history of the rule, however, opened
with the Court's decision in Wolf v. Colorado, 338 U. S. 25 (1949). Although that decision held that the security of one's
person and privacy protected by the Fourth Amendment was "implicit
in the concept of ordered liberty' and as such enforceable
against the States through the Due Process Clause" of the
Fourteenth Amendment, id. at 338 U. S. 27 -28,
quoting Palko v. Connecticut, 302 U.
S. 319 , 302 U. S. 325 (1937), the Court went on, in what can only be regarded as a tour de force of constitutional obfuscation, to say that
the "ways of enforcing such a basic right raise questions of a
different order," 338 U.S. at 338 U. S. 28 .
Notwithstanding the force of the Weeks doctrine that the
Fourth Amendment required exclusion, a state court was free to
admit illegally seized evidence, according to the Court in Wolf, so long as the State had devised some other
"effective" means of vindicating a defendant's Fourth Amendment
rights. 338 U.S. at 338 U. S.
31 . Twelve years later, in Mapp v. Ohio, 367 U.
S. 643 (1961), however, the Court restored the original
understanding of the Weeks case by overruling the holding
of Wolf and repudiating its rationale. Although, in the
course of reaching this conclusion, the Court in Mapp responded at certain points to the question, first raised in Wolf, of whether the exclusionary rule was an "effective"
remedy compared to alternative means of enforcing the right, see 367 U.S. at 367 U. S.
651 -653, it nevertheless expressly held that

															"all evidence obtained by searches and seizures in violation of
the Constitution is, by that same authority, inadmissible
in a state court." Id. at 367 U. S. 655 (emphasis added). In the Court's view, the exclusionary rule was
not one among a range of options to be selected at the discretion
of judges; it was "an essential part of both the Fourth and
Fourteenth Amendments." Id. at 367 U. S. 657 .
Rejection of the Wolf approach was constitutionally
required, the Court explained, because

															"the admission of the new constitutional right by Wolf could not consistently tolerate denial of Page 468 U. S. 940 its most important constitutional privilege, namely, the
exclusion of the evidence which an accused had been forced to give
by reason of the unlawful seizure. To hold otherwise is to grant
the right but in reality to withhold its privilege and
enjoyment."

															367 U.S. at 367 U. S. 656 .
Indeed, no other explanation suffices to account for the Court's
holding in Mapp, since the only possible predicate for the Court's
conclusion that the States were bound by the Fourteenth Amendment
to honor the Weeks doctrine is that the exclusionary rule
was "part and parcel of the Fourth Amendment's limitation upon
[governmental] encroachment of individual privacy." 367 U.S. at 367 U. S. 651 .
[ Footnote 2/7 ]

															Despite this clear pronouncement, however, the Court since Calandra has gradually pressed the deterrence rationale
for the rule back to center stage. See, e.g., United States v.
Peltier, 422 U. S. 531 (1975); United States v. Janis, 428 U.
S. 433 (1976); Stone v. Powell, 428 U.
S. 465 (1976). The various arguments advanced by the
Court in this campaign have only strengthened my conviction that
the deterrence theory is both misguided and unworkable. First, Page 468 U. S. 941 the Court has frequently bewailed the "cost" of excluding
reliable evidence. In large part, this criticism rests upon a
refusal to acknowledge the function of the Fourth Amendment itself.
If nothing else, the Amendment plainly operates to disable the
government from gathering information and securing evidence in
certain ways. In practical terms, of course, this restriction of
official power means that some incriminating evidence inevitably
will go undetected if the government obeys these constitutional
restraints. It is the loss of that evidence that is the "price" our
society pays for enjoying the freedom and privacy safeguarded by
the Fourth Amendment. Thus, some criminals will go free not, in
Justice (then Judge) Cardozo's misleading epigram, "because the
constable has blundered," People v. Defore, 242 N.Y. 13,
21, 150 N.E. 585, 587 (1926), but rather because official
compliance with Fourth Amendment requirements makes it more
difficult to catch criminals. Understood in this way, the Amendment
directly contemplates that some reliable and incriminating evidence
will be lost to the government; therefore, it is not the
exclusionary rule, but the Amendment itself, that has imposed this
cost. [ Footnote 2/8 ] Page 468 U. S. 942 In addition, the Court's decisions over the past decade have
made plain that the entire enterprise of attempting to assess the
benefits and costs of the exclusionary rule in various contexts is
a virtually impossible task for the judiciary to perform honestly
or accurately. Although the Court's language in those cases
suggests that some specific empirical basis may support its
analyses, the reality is that the Court's opinions represent
inherently unstable compounds of intuition, hunches, and occasional
pieces of partial and often inconclusive data. In Calandra, for example, the Court, in considering whether
the exclusionary rule should apply in grand jury proceedings, had
before it no concrete evidence whatever concerning the impact that
application of the rule in such proceedings would have either in
terms of the long-term costs or the expected benefits. To the
extent empirical data are available regarding the general costs and
benefits of the exclusionary rule, such data have shown, on the one
hand, as the Court acknowledges today, that the costs are not as
substantial as critics have asserted in the past, see ante at 468 U. S.
907 -908, n. 6, and, on the other hand, that, while the
exclusionary rule may well have certain deterrent effects, it is
extremely difficult to determine with any degree of precision
whether the incidence of unlawful conduct by police is now lower
than it was prior to Mapp. See United States v.
Janis, 428 U.S. at 428 U. S.
449 -453, and n. 22; Stone v. Powell, 428 U.S.
at 428 U. S. 492 ,
n. 32. [ Footnote 2/9 ] The Page 468 U. S. 943 Court has sought to turn this uncertainty to its advantage by
casting the burden of proof upon proponents of the rule, see,
e.g., United States v. Janis, supra, at 428 U. S.
453 -454. "Obviously," however,

															"the assignment of the burden of proof on an issue where
evidence does not exist and cannot be obtained is
outcome-determinative. [The] assignment of the burden is merely a
way of announcing a predetermined conclusion. [ Footnote 2/10 ]"

															By remaining within its redoubt of empiricism and by basing the
rule solely on the deterrence rationale, the Court has robbed the
rule of legitimacy. A doctrine that is explained as if it were an
empirical proposition, but for which there is only limited
empirical support, is both inherently unstable and an easy mark for
critics. The extent of this Court's fidelity to Fourth Amendment
requirements, however, should not turn on such statistical
uncertainties. I share the view, expressed by Justice Stewart for
the Court in Faretta v. California, 422 U.
S. 806 (1975), that "[p]ersonal liberties are not rooted
in the law of averages." Id. at 422 U. S. 834 .
Rather than seeking to give effect to the liberties secured by the
Fourth Amendment through guesswork about deterrence, the Court
should restore to its proper place the principle framed 70 years
ago in Weeks that an individual whose privacy has been
invaded in violation of the Fourth Amendment has a right grounded
in that Amendment to prevent the government from subsequently
making use of any evidence so obtained. Page 468 U. S. 944 II Application of that principle clearly requires affirmance in the
two cases decided today. In the first, United States v.
Leon, No. 82-1771, it is conceded by the Government and
accepted by the Court that the affidavit filed by the police
officers in support of their application for a search warrant
failed to provide a sufficient basis on which a neutral and
detached magistrate could conclude that there was probable cause to
issue the warrant. Specifically, it is conceded that the officers'
application for a warrant was based in part on information supplied
by a confidential informant of unproven reliability that was over
five months old by the time it was relayed to the police. Although
the police conducted an independent investigation on the basis of
this tip, both the District Court and the Court of Appeals
concluded that the additional information gathered by the officers
failed to corroborate the details of the informant's tip, and was
"as consistent with innocence as . . . with guilt." App. to Pet.
for Cert. 10a. The warrant, therefore, should never have issued.
Stripped of the authority of the warrant, the conduct of these
officers was plainly unconstitutional -- it amounted to nothing
less than a naked invasion of the privacy of respondents' homes
without the requisite justification demanded by the Fourth
Amendment. In order to restore the Government to the position it
would have occupied had this unconstitutional search not occurred,
therefore, it was necessary that the evidence be suppressed. As we
said in Coolidge v. New Hampshire, 403 U.
S. 443 (1971), the Warrant Clause is not

															"an inconvenience to be somehow 'weighed' against the claims of
police efficiency. It is, or should be, an important working part
of our machinery of government, operating as a matter of course to
check the 'well-intentioned but mistakenly overzealous executive
officers' who are part of any system of law enforcement." Id. at 403 U. S. 481 (footnote omitted).

															A close examination of the facts of this case reveals that this
is neither an extraordinary nor indeed a very costly step. Page 468 U. S. 945 The warrant had authorized a search for cocaine, methaqualone
tablets, and miscellaneous narcotics paraphernalia at several
locations: a condominium at 7902 Via Magdalena in Los Angeles; a
residence at 620 Price Drive in Burbank; a residence at 716 South
Sunset Canyon in Burbank; and four automobiles owned respectively
by respondents Leon, Sanchez, Stewart, and Del Castillo. App.
31-33. Pursuant to this warrant, the officers seized approximately
four pounds of cocaine and over 1,000 methaqualone tablets from the
Via Magdalena condominium, nearly one pound of cocaine from the
Sunset Canyon residence, about an ounce of cocaine from the Price
Drive residence, and certain paraphernalia from Del Castillo's and
Stewart's automobiles. On the basis of this and other evidence, the
four respondents were charged with violating 21 U.S.C. § 846 for
conspiring to possess and distribute cocaine, and § 841(a)(1) for
possessing methaqualone and cocaine with intent to distribute. The
indictment specifically alleged that respondents had maintained the
Via Magdalena condominium as a storage area for controlled
substances which they distributed to prospective purchasers. App.
27-28.

															At the suppression hearing, the District Court determined that
none of the respondents had a sufficient expectation of privacy to
contest the search of the Via Magdalena condominium, that
respondents Stewart and Sanchez could challenge the search of their
home at Price Drive, that respondent Leon was entitled to challenge
the search of his home at Sunset Canyon, and that respondents Del
Castillo and Stewart could contest the search of their cars. Given
its finding that probable cause to issue the warrant was lacking,
the District Court ruled that the evidence from the Price Drive
residence could not be used against respondents Stewart and
Sanchez, that evidence from the Sunset Canyon residence could not
be used against Leon, and that evidence obtained from both Del
Castillo's and Stewart's automobiles could not be used against
them. App. to Pet. for Cert. 10a-13a. Page 468 U. S. 946 The tenor of the Court's opinion suggests that this order
somehow imposed a grave and presumably unjustifiable cost on
society. Such a suggestion, however, is a gross exaggeration. Since
the indictment focused upon a conspiracy among all respondents to
use the Via Magdalena condominium as a storage area for controlled
substances, and since the bulk of the evidence seized was from that
condominium and was plainly admissible under the District Court's
order, the Government would clearly still be able to present a
strong case to the jury following the court's suppression order. I
emphasize these details not to suggest how the Government's case
would fare before the jury, but rather to clarify a point that is
lost in the Court's rhetorical excesses over the costs of the
exclusionary rule -- namely, that the suppression of evidence will
certainly tend to weaken the Government's position, but it will
rarely force the Government to abandon a prosecution. Cf.
infra, at 468 U. S.
950 -951, and n. 11. In my view, a doctrine that
preserves intact the constitutional rights of the accused, and, at
the same time, is sufficiently limited to permit society's
legitimate and pressing interest in criminal law enforcement to be
served should not be so recklessly discarded. It is a doctrine that
gives life to the

															"very heart of the Fourth Amendment directive: that . . . a
governmental search and seizure should represent both the efforts
of the officer to gather evidence of wrongful acts and the judgment
of the magistrate that the collected evidence is sufficient to
justify invasion of a citizen's private premises." United States v. United States District Court, 407 U. S. 297 , 407 U. S. 316 (1972). In the second case before the Court, Massachusetts v.
Sheppard, No. 82-963, the State concedes and the Court accepts
that the warrant issued to search respondent's home completely
failed to state with particularity the things to be seized. Indeed,
the warrant expressly and particularly described things such as
"controlled substance[s]" and "other paraphernalia used in, for, or
in connection with the unlawful possession or use of any controlled
substance" that the police had no reason whatsoever to believe were
to be found in Page 468 U. S. 947 respondent's home. App. 17a. Given the Fourth Amendment's
requirement that "no Warrants shall issue, but upon probable cause
. . . and particularly describing the . . . things to be seized,"
this warrant should never have been issued. The police who entered
respondent's home, therefore, were without constitutional authority
to do so.

															Although the Court's opinion tends to overlook this fact, the
requirement of particularity is not a mere "technicality," it is an
express constitutional command. Ybarra v. Illinois, 444 U. S. 85 , 444 U. S. 92 (1979); Lo-Ji Sales, Inc. v. New York, 442 U.
S. 319 (1979); Stanford v. Texas, 379 U.
S. 476 (1965); Marron v. United States, 275 U. S. 192 , 275 U. S. 196 (1927). The purpose of that requirement is to prevent precisely the
kind of governmental conduct that the faulty warrant at issue here
created a grave risk of permitting -- namely, a search that was not
narrowly and particularly limited to the things that a neutral and
detached magistrate had reason to believe might be found at
respondent's home. Although it is true, as JUSTICE STEVENS
observes, see post at 468 U. S. 964 ,
that the affidavit submitted by the police set forth with
particularity those items that they sought authority to search for,
it is nevertheless clear that the warrant itself -- the document
which actually gave the officers legal authority to invade
respondent's privacy -- made no mention of these items. And,
although it is true that the particular officers who applied for
the warrant also happened to execute it and did so in accordance
with the limits proposed in their affidavit, this happenstance
should have no bearing on the central question whether these
officers secured that prior judicial authority to conduct their
search required by the Fourth Amendment. As we made clear in United States v. United States District Court, supra, at 407 U. S. 317 (footnote omitted), "[t]he Fourth Amendment contemplates a prior
judicial judgment, not the risk that executive discretion may be
reasonably exercised." See also Katz v. United States, 389 U. S. 347 , 389 U. S.
356 -357 (1967) ("this Court has never sustained a search
upon the sole ground that officers reasonably expected to find
evidence of a particular crime Page 468 U. S. 948 and voluntarily confined their activities to the least intrusive
means consistent with that end"). Had the warrant actually been
enforced by officers other than those who prepared the affidavit,
the same result might not have occurred; indeed, the wholly
erroneous nature of the warrant might have led such officers to
feel at liberty to roam throughout respondent's home in search of
drugs. Cf. Whiteley v. Warden, 401 U.
S. 560 (1971). I therefore fail to see how a search
pursuant to such a fundamentally defective warrant can be
characterized as "reasonable . "

															What the Framers of the Bill of Rights sought to accomplish
through the express requirements of the Fourth Amendment was to
define precisely the conditions under which government agents could
search private property so that citizens would not have to depend
solely upon the discretion and restraint of those agents for the
protection of their privacy. Although the self-restraint and care
exhibited by the officers in this case is commendable, that alone
can never be a sufficient protection for constitutional liberties.
I am convinced that it is not too much to ask that an attentive
magistrate take those minimum steps necessary to ensure that every
warrant he issues describes with particularity the things that his
independent review of the warrant application convinces him are
likely to be found in the premises. And I am equally convinced that
it is not too much to ask that well-trained and experienced police
officers take a moment to check that the warrant they have been
issued at least describes those things for which they have sought
leave to search. These convictions spring not from my own view of
sound criminal law enforcement policy, but are instead compelled by
the language of the Fourth Amendment and the history that led to
its adoption. III Even if I were to accept the Court's general approach to the
exclusionary rule, I could not agree with today's result. Page 468 U. S. 949 There is no question that, in the hands of the present Court,
the deterrence rationale has proved to be a powerful tool for
confining the scope of the rule. In Calandra, for example,
the Court concluded that the "speculative and undoubtedly minimal
advance in the deterrence of police misconduct," was insufficient
to outweigh the "expense of substantially impeding the role of the
grand jury." 414 U.S. at 414 U. S.
351 -352. In Stone v. Powell, the Court found
that

															"the additional contribution, if any, of the consideration of
search and seizure claims of state prisoners on collateral review
is small in relation to the costs."

															428 U.S. at 428 U. S. 493 .
In United States v. Janis, 428 U.
S. 433 (1976), the Court concluded that

															"exclusion from federal civil proceedings of evidence unlawfully
seized by a state criminal enforcement officer has not been shown
to have a sufficient likelihood of deterring the conduct of the
state police so that it outweighs the societal costs imposed by the
exclusion." Id. at 428 U. S. 454 .
And in an opinion handed down today, the Court finds that the

															"balance between costs and benefits comes out against applying
the exclusionary rule in civil deportation hearings held by the
[Immigration and Naturalization Service]." INS v. Lopez-Mendoza, post at 468 U. S.
1050 .

															Thus, in this bit of judicial stagecraft, while the sets
sometimes change, the actors always have the same lines. Given this
well-rehearsed pattern, one might have predicted with some
assurance how the present case would unfold. First there is the
ritual incantation of the "substantial social costs" exacted by the
exclusionary rule, followed by the virtually foreordained
conclusion that, given the marginal benefits, application of the
rule in the circumstances of these cases is not warranted. Upon
analysis, however, such a result cannot be justified even on the
Court's own terms.

															At the outset, the Court suggests that society has been asked to
pay a high price -- in terms either of setting guilty persons free
or of impeding the proper functioning of trials -- as a result of
excluding relevant physical evidence in cases Page 468 U. S. 950 where the police, in conducting searches and seizing evidence,
have made only an "objectively reasonable" mistake concerning the
constitutionality of their actions. See ante at 468 U. S.
907 -908. But what evidence is there to support such a
claim? Significantly, the Court points to none, and, indeed, as the
Court acknowledges, see ante at 468 U. S.
907 -908, n. 6, recent studies have demonstrated that the
"costs" of the exclusionary rule -- calculated in terms of dropped
prosecutions and lost convictions -- are quite low. Contrary to the
claims of the rule's critics that exclusion leads to "the release
of countless guilty criminals," Bivens v. Six Unknown Federal
Narcotics Agents, 403 U. S. 388 , 403 U. S. 416 (1971) (BURGER, C.J., dissenting), these studies have demonstrated
that federal and state prosecutors very rarely drop cases because
of potential search and seizure problems. For example, a 1979 study
prepared at the request of Congress by the General Accounting
Office reported that only 0.4% of all cases actually declined for
prosecution by federal prosecutors were declined primarily because
of illegal search problems. Report of the Comptroller General of
the United States, Impact of the Exclusionary Rule on Federal
Criminal Prosecutions 14 (1979). If the GAO data are restated as a
percentage of all arrests, the study shows that only 0.2% of all
felony arrests are declined for prosecution because of potential
exclusionary rule problems. See Davies, A Hard Look at
What We Know (and Still Need to Learn) About the "Costs" of the
Exclusionary Rule: The NU Study and Other Studies of "Lost"
Arrests, 1983 A.B.F.Res.J. 611, 635. [ Footnote 2/11 ] Of course, these data describe Page 468 U. S. 951 only the costs attributable to the exclusion of evidence in all
cases; the costs due to the exclusion of evidence in the narrower
category of cases where police have made objectively reasonable
mistakes must necessarily be even smaller. The Court, however,
ignores this distinction and mistakenly weighs the aggregated costs
of exclusion in all cases, irrespective of the circumstances that
led to exclusion, see ante at 468 U. S. 907 ,
against the potential benefits associated with only those cases in
which evidence is excluded because police reasonably but mistakenly
believe that their conduct does not violate the Fourth Amendment, see ante at 468 U. S.
915 -921. When such faulty scales are used, it is little
wonder that the balance tips in favor of restricting the
application of the rule. Page 468 U. S. 952 What then supports the Court's insistence that this evidence be
admitted? Apparently, the Court's only answer is that, even though
the costs of exclusion are not very substantial, the potential
deterrent effect in these circumstances is so marginal that
exclusion cannot be justified. The key to the Court's conclusion in
this respect is its belief that the prospective deterrent effect of
the exclusionary rule operates only in those situations in which
police officers, when deciding whether to go forward with some
particular search, have reason to know that their planned conduct
will violate the requirements of the Fourth Amendment. See
ante at 468 U. S.
919 -921. If these officers in fact understand (or
reasonably should understand because the law is well settled) that
their proposed conduct will offend the Fourth Amendment and that,
consequently, any evidence they seize will be suppressed in court,
they will refrain from conducting the planned search. In those
circumstances, the incentive system created by the exclusionary
rule will have the hoped-for deterrent effect. But in situations
where police officers reasonably (but mistakenly) believe that
their planned conduct satisfies Fourth Amendment requirements --
presumably either (a) because they are acting on the basis of an
apparently valid warrant, or (b) because their conduct is only
later determined to be invalid as a result of a subsequent change
in the law or the resolution of an unsettled question of law --
then such officers will have no reason to refrain from conducting
the search, and the exclusionary rule will have no effect.

															At first blush, there is some logic to this position.
Undoubtedly, in the situation hypothesized by the Court, the
existence of the exclusionary rule cannot be expected to have any
deterrent effect on the particular officers at the moment they are
deciding whether to go forward with the search. Indeed, the
subsequent exclusion of any evidence seized under such
circumstances appears somehow "unfair" to the particular officers
involved. As the Court suggests, these officers have acted in what
they thought was an appropriate Page 468 U. S. 953 and constitutionally authorized manner, but then the fruit of
their efforts is nullified by the application of the exclusionary
rule. Ante at 468 U. S.
920 -921.

															The flaw in the Court's argument, however, is that its logic
captures only one comparatively minor element of the generally
acknowledged deterrent purposes of the exclusionary rule. To be
sure, the rule operates to some extent to deter future misconduct
by individual officers who have had evidence suppressed in their
own cases. But what the Court overlooks is that the deterrence
rationale for the rule is not designed to be, nor should it be
thought of as, a form of "punishment" of individual police officers
for their failures to obey the restraints imposed by the Fourth
Amendment. See United States v. Peltier, 422 U.S. at 422 U. S.
556 -557 (BRENNAN, J., dissenting). Instead, the chief
deterrent function of the rule is its tendency to promote
institutional compliance with Fourth Amendment requirements on the
part of law enforcement agencies generally. [ Footnote 2/12 ] Thus, as the Court has previously Page 468 U. S. 954 recognized,

															"over the long-term, [the] demonstration [provided by the
exclusionary rule] that our society attaches serious consequences
to violation of constitutional rights is thought to encourage those
who formulate law enforcement policies, and the officers who
implement them, to incorporate Fourth Amendment ideals into their
value system." Stone v. Powell, 428 U.S. at 428 U. S. 492 .
It is only through such an institutionwide mechanism that
information concerning Fourth Amendment standards can be
effectively communicated to rank-and-file officers. [ Footnote 2/13 ] Page 468 U. S. 955 If the overall educational effect of the exclusionary rule is
considered, application of the rule to even those situations in
which individual police officers have acted on the basis of a
reasonable but mistaken belief that their conduct was authorized
can still be expected to have a considerable long-term deterrent
effect. If evidence is consistently excluded in these
circumstances, police departments will surely be prompted to
instruct their officers to devote greater care and attention to
providing sufficient information to establish probable cause when
applying for a warrant, and to review with some attention the form
of the warrant that they have been issued, rather than
automatically assuming that whatever document the magistrate has
signed will necessarily comport with Fourth Amendment
requirements.

															After today's decisions, however, that institutional incentive
will be lost. Indeed, the Court's "reasonable mistake" exception to
the exclusionary rule will tend to put a premium on police
ignorance of the law. Armed with the assurance provided by today's
decisions that evidence will always be admissible whenever an
officer has "reasonably" relied upon a warrant, police departments
will be encouraged to train officers that, if a warrant has simply
been signed, it is reasonable, without more, to rely on it. Since
in close cases there will no longer be any incentive to err on the
side of constitutional behavior, police would have every reason to
adopt a "let's-wait-until-it's-decided" approach in situations in
which there is a question about a warrant's validity or the basis
for its issuance. Cf. United States v. Johnson, 457 U. S. 537 , 457 U. S. 561 (1982). [ Footnote 2/14 ] Page 468 U. S. 956 Although the Court brushes these concerns aside, a host of grave
consequences can be expected to result from its decision to carve
this new exception out of the exclusionary rule. A chief
consequence of today's decisions will be to convey a clear and
unambiguous message to magistrates that their decisions to issue
warrants are now insulated from subsequent judicial review.
Creation of this new exception for good faith reliance upon a
warrant implicitly tells magistrates that they need not take much
care in reviewing warrant applications, since their mistakes will,
from now on, have virtually no consequence: if their decision to
issue a warrant was correct, the evidence will be admitted; if
their decision was incorrect but the police relied in good faith on
the warrant, the evidence will also be admitted. Inevitably, the
care and attention devoted to such an inconsequential chore will
dwindle. Although the Court is correct to note that magistrates do
not share the same stake in the outcome of a criminal case as the
police, they nevertheless need to appreciate that their role is of
some moment in order to continue performing the important task of
carefully reviewing warrant applications. Today's decisions
effectively remove that incentive. [ Footnote 2/15 ] Page 468 U. S. 957 Moreover, the good faith exception will encourage police to
provide only the bare minimum of information in future warrant
applications. The police will now know that, if they can secure a
warrant, so long as the circumstances of its issuance are not
"entirely unreasonable," ante at 468 U. S. 923 ,
all police conduct pursuant to that warrant will be protected from
further judicial review. [ Footnote
2/16 ] The clear incentive that operated in the past to
establish probable cause adequately because reviewing courts would
examine the magistrate's judgment carefully, see, e.g., Franks
v. Delaware, 438 U. S. 154 , 438 U. S.
169 -170 (1978); Jones v. United States, 362 U. S. 257 , 362 U. S.
271 -272 (1960); Giordenello v. United States, 357 U. S. 480 , 357 U. S. 483 (1958), has now been so completely vitiated that the police need
only show that it was not "entirely unreasonable" under the
circumstances Page 468 U. S. 958 of a particular case for them to believe that the warrant they
were issued was valid. See ante at 468 U. S. 923 .
The long-run effect unquestionably will be to undermine the
integrity of the warrant process.

															Finally, even if one were to believe, as the Court apparently
does, that police are hobbled by inflexible and hypertechnical
warrant procedures, today's decisions cannot be justified. This is
because, given the relaxed standard for assessing probable cause
established just last Term in Illinois v. Gates, 462 U. S. 213 (1983), the Court's newly fashioned good faith exception, when
applied in the warrant context, will rarely, if ever, offer any
greater flexibility for police than the Gates standard
already supplies. In Gates, the Court held that

															"[t]he task of the issuing magistrate is simply to make a
practical, common sense decision whether, given all the
circumstances set forth in the affidavit before him, . . . there is
a fair probability that contraband or evidence of a crime will be
found in a particular place." Id. at 462 U. S. 238 .
The task of a reviewing court is confined to determining whether
"the magistrate had a substantial basis for . . . conclud[ing]'
that probable cause existed." Ibid. Given such a relaxed
standard, it is virtually inconceivable that a reviewing court,
when faced with a defendant's motion to suppress, could first find
that a warrant was invalid under the new Gates standard,
but then, at the same time, find that a police officer's reliance
on such an invalid warrant was nevertheless "objectively
reasonable" under the test announced today. [ Footnote 2/17 ] Because the two standards overlap so
completely, it is unlikely that a warrant could be found invalid
under Gates and yet the police reliance upon it could be
seen as objectively reasonable; otherwise, we would have to
entertain the mind-boggling Page 468 U. S. 959 concept of objectively reasonable reliance upon an objectively
unreasonable warrant.

															This paradox, as JUSTICE STEVENS suggests, see post at 468 U. S.
961 -962, perhaps explains the Court's unwillingness to
remand No. 82-1771 for reconsideration in light of Gates, for it is quite likely that, on remand, the Court of Appeals would
find no violation of the Fourth Amendment, thereby demonstrating
that the supposed need for the good faith exception in this context
is more apparent than real. Therefore, although the Court's
decisions are clearly limited to the situation in which police
officers reasonably rely upon an apparently valid warrant in
conducting a search, I am not at all confident that the exception
unleashed today will remain so confined. Indeed, the full impact of
the Court's regrettable decisions will not be felt until the Court
attempts to extend this rule to situations in which the police have
conducted a warrantless search solely on the basis of their own
judgment about the existence of probable cause and exigent
circumstances. When that question is finally posed, I for one will
not be surprised if my colleagues decide once again that we simply
cannot afford to protect Fourth Amendment rights. IV When the public, as it quite properly has done in the past as
well as in the present, demands that those in government increase
their efforts to combat crime, it is all too easy for those
government officials to seek expedient solutions. In contrast to
such costly and difficult measures as building more prisons,
improving law enforcement methods, or hiring more prosecutors and
judges to relieve the overburdened court systems in the country's
metropolitan areas, the relaxation of Fourth Amendment standards
seems a tempting, costless means of meeting the public's demand for
better law enforcement. In the long run, however, we as a society
pay a heavy price for such expediency, because, as Justice Jackson
observed, the rights guaranteed in the Fourth Amendment Page 468 U. S. 960 "are not mere second-class rights, but belong in the catalog of
indispensable freedoms." Brinegar v. United States, 338 U. S. 160 , 338 U. S. 180 (1949) (dissenting opinion). Once lost, such rights are difficult
to recover. There is hope, however, that in time this or some later
Court will restore these precious freedoms to their rightful place
as a primary protection for our citizens against overreaching
officialdom. I dissent. * [This opinion applies also to No. 82-963, Massachusetts v.
Sheppard, post, p. 468 U. S.
981 .]

															[ Footnote 2/1 ] See, e.g., United States v. Peltier, 422 U.
S. 531 , 422 U. S. 544 (1975) (BRENNAN, J., dissenting); United States v. Janis, 428 U. S. 433 , 428 U. S. 460 (1976) (BRENNAN, J., dissenting); Stone v. Powell, 428 U. S. 465 , 428 U. S. 502 (1976) (BRENNAN, J., dissenting); Michigan v. DeFillippo, 443 U. S. 31 , 443 U. S. 41 (1979) (BRENNAN, J., dissenting); United States v. Havens, 446 U. S. 620 , 446 U. S. 629 (1980) (BRENNAN, J., dissenting).

															[ Footnote 2/2 ] See, e.g., Wilkey, The Exclusionary Rule: Why Suppress
Valid Evidence?, 62 Judicature 215 (1978); S. Schlesinger,
Exclusionary Injustice (1977).

															[ Footnote 2/3 ]

															In deciding to enforce the exclusionary rule as a matter of
state law, the California Supreme Court clearly recognized this
point:

															"When, as in the present case, the very purpose of an illegal
search and seizure is to get evidence to introduce at a trial, the
success of the lawless venture depends entirely on the court's
lending its aid by allowing the evidence to be introduced. It is no
answer to say that a distinction should be drawn between the
government acting as law enforcer and the gatherer of evidence and
the government acting as judge." People v. Cahan, 44 Cal. 2d
434 , 445, 282 P.2d 905, 912 (1955).

															For a thoughtful examination of this point, see Schrock
& Welsh, Up from Calandra: The Exclusionary Rule as a
Constitutional Requirement, 59 Minn.L.Rev. 251, 289-307 (1974).

															[ Footnote 2/4 ]

															Examination of the early state declarations of rights which
formed the models for the Fourth Amendment reveals that they were
aimed as much at explicitly limiting the manner in which government
could gather evidence as at protecting individual privacy. For
example, the Massachusetts Constitution of 1780 provided:

															"Every subject has a right to be secure from all unreasonable
searches, and seizures, of his person, his houses, his papers, and
his possessions. All warrants, therefore, are contrary to this
right, if the cause or foundation of them be not previously
supported by oath or affirmation; and if the order in the warrant
to a civil Officer, to make search in suspected places, or to
arrest one or more suspected persons, or to seize their property,
be not accompanied with a special designation of the persons or
objects of search, arrest, or seizure: and no warrant ought to be
issued, but in cases, and with the formalities prescribed by the
laws."

															Art. XIV of the Declaration of Rights of 1780. See
generally T. Taylor, Two Studies in Constitutional
Interpretation 41-43 (1969); N. Lasson, The History and Development
of the Fourth Amendment to the United States Constitution 51-105
(1970); J. Lanynski, Search and Seizure and the Supreme Court: A
Study in Constitutional Interpretation 30-48 (1966); Stewart, The
Road to Mapp v. Ohio and Beyond: The Origins, Development,
and Future of the Exclusionary Rule in Search and Seizure Cases, 83
Colum.L.Rev. 1365, 1369 (1983).

															[ Footnote 2/5 ]

															In Silverthorne Lumber Co. v. United States, 251 U. S. 385 (1920), the Court expressly recognized this point in rejecting the
Government's contention that it should be permitted to make use of
knowledge obtained in violation of the Fourth Amendment:

															"The Government now, while in form repudiating and condemning
the illegal seizure, seeks to maintain its right to avail itself of
the knowledge obtained by that means which otherwise it would not
have had."

															"The proposition could not be presented more nakedly. It is
that, although of course its seizure was an outrage which the
Government now regrets, it may study the papers before it returns
them, copy them, and then may use the knowledge that it has gained
to call upon the owners in a more regular form to produce them. . .
. In our opinion, such is not the law. It reduces the Fourth
Amendment to a form of words. The essence of a provision
forbidding the acquisition of evidence in a certain way is that not
merely evidence so acquired shall not be used before the Court, but
that it shall not be used at all. " Id. at 251 U. S.
391 -392 (citations omitted) (emphasis added).

															[ Footnote 2/6 ] See generally Kamisar, Does (Did) (Should) The
Exclusionary Rule Rest on a "Principled Basis" Rather than an
"Empirical Proposition"?, 16 Creighton L.Rev. 565, 598-599 (1983);
Mertens & Wasserstrom, The Good Faith Exception to the
Exclusionary Rule: Deregulating the Police and Derailing the Law,
70 Geo. L.J. 365, 379-380 (1981).

															[ Footnote 2/7 ]

															Indeed, the Court in Mapp expressly noted that the
"factual considerations" raised in Wolf concerning the
effectiveness of alternative remedies "are not basically relevant
to a decision that the exclusionary rule is an essential ingredient
of the Fourth Amendment." 367 U.S. at 367 U. S. 651 .
It is true that, in Linkletter v. Walker, 381 U.
S. 618 (1965), in holding that Mapp was not to
be applied retroactively, the Court described the exclusionary rule
as the "only effective deterrent to lawless police action," 381
U.S. at 381 U. S. 636 ,
thereby suggesting that the rule rested on a deterrence rationale.
But, as I have explained on another occasion,

															"[t]he emphasis upon deterrence in Linkletter must be
understood in the light of the crucial fact that the States had
justifiably relied from 1949 to 1961 upon Wolf . . . . ,
and consequently, that application of Mapp would have
required the wholesale release of innumerable convicted prisoners,
few of whom could have been successfully retried. In that
circumstance, Linkletter held not only that retrospective
application of Mapp would not further the goal of
deterrence, but also that it would not further 'the administration
of justice and the integrity of the judicial process.' 381 U.S. at 381 U. S. 637 ." United State v. Calandra, 414 U.
S. 338 , 414 U. S.
359 -360 (1974) (dissenting opinion).

															[ Footnote 2/8 ]

															Justice Stewart has explained this point in detail in a recent
article:

															"Much of the criticism leveled at the exclusionary rule is
misdirected; it is more properly directed at the Fourth Amendment
itself. It is true that, as many observers have charged, the effect
of the rule is to deprive the courts of extremely relevant, often
direct evidence of the guilt of the defendant. But these same
critics fail to acknowledge that, in many instances, the same
extremely relevant evidence would not have been obtained had the
police officer complied with the commands of the fourth amendment
in the first place. . . ."

															". . . The exclusionary rule places no limitations on the
actions of the police. The fourth amendment does. The inevitable
result of the Constitution's prohibition against unreasonable
searches and seizures and its requirement that no warrant shall
issue but upon probable cause is that police officers who obey its
strictures will catch fewer criminals. . . . [T]hat is the price
the framers anticipated and were willing to pay to ensure the
sanctity of the person, the home, and property against unrestrained
governmental power."

															Stewart, 83 Colum.L.Rev. at 1392-1393. See also Dellinger, Of Rights and Remedies: The Constitution as a Sword, 85
Harv.L.Rev. 1532, 1563 (1972) ("Under the exclusionary rule, a
court attempts to maintain the status quo that would have
prevailed if the constitutional requirement had been obeyed").

															[ Footnote 2/9 ] See generally on this point, Davies, A Hard Look at
What We Know (and Still Need to Learn) About the "Costs" of the
Exclusionary Rule: The NU Study and Other Studies of"Lost" Arrests,
1983 A.B.F.Res.J. 611, 627-629; Canon, Ideology and Reality in the
Debate over the Exclusionary Rule: A Conservative Argument for its
Retention, 23 S.Tex.L.J. 559, 561-563 (1982); Critique, On the
Limitations of Empirical Evaluations of the Exclusionary Rule: A
Critique of the Spiotto Research and United States v.
Calandra, 69 NW.U.L.Rev. 740 (1974).

															[ Footnote 2/10 ]

															Dworkin, Fact Style Adjudication and the Fourth Amendment: The
Limits of Lawyering, 48 Ind.L.J. 329, 332-333 (1973). See
also White, Forgotten Points in the "Exclusionary Rule"
Debate, 81 Mich.L.Rev. 1273, 1281-1282 (1983) (balancing of
deterrent benefits and costs is an "inquiry [that] can never be
performed in an adequate way, and the reality is thus that the
decision must rest not upon those grounds, but upon prior
dispositions or unarticulated intuitions that are never
justified"); Canon, supra, at 564; Kamisar, 16 Creighton
L.Rev. at 646.

															[ Footnote 2/11 ]

															In a series of recent studies, researchers have attempted to
quantify the actual costs of the rule. A recent National Institute
of Justice study based on data for the 4-year period 1976-1979
gathered by the California Bureau of Criminal Statistics showed
that 4.8% of all cases that were declined for prosecution by
California prosecutors were rejected because of illegally seized
evidence. National Institute of Justice, Criminal Justice Research
Report -- The Effects of the Exclusionary Rule: A Study in
California 1 (1982). However, if these data are calculated as a
percentage of all arrests, they show that only 0.8% of all arrests
were rejected for prosecution because of illegally seized evidence. See Davies, 1983 A.B.F.Res.J. at 619.

															In another measure of the rule's impact -- the number of
prosecutions that are dismissed or result in acquittals in cases
where evidence has been excluded -- the available data again show
that the Court's past assessment of the rule's costs has generally
been exaggerated. For example, a study based on data from nine
mid-sized counties in Illinois, Michigan, and Pennsylvania reveals
that motions to suppress physical evidence were filed in
approximately 5% of the 7,500 cases studied, but that such motions
were successful in only 0.7% of all these cases. Nardulli, The
Societal Cost of the Exclusionary Rule: An Empirical Assessment,
1983 A.B.F.Res.J. 585, 596. The study also shows that only 0.6% of
all cases resulted in acquittals because evidence had been
excluded. Id. at 600. In the GAO study, suppression
motions were filed in 10.5% of all federal criminal cases surveyed,
but of the motions filed, approximately 80-90% were denied. GAO
Report, at 8, 10. Evidence was actually excluded in only 1.3% of
the cases studied, and only 0.7% of all cases resulted in
acquittals or dismissals after evidence was excluded. Id. at 9-11. See Davies, supra, at 660. And in
another study based on data from cases during 1978 and 1979 in San
Diego and Jacksonville, it was shown that only 1% of all cases
resulting in nonconviction were caused by illegal searches. F.
Feeney, F. Dill, & A. Weir, Arrests Without Conviction: How
Often They Occur and Why (National Institute of Justice 1983). See generally Davies, supra, at 663.

															[ Footnote 2/12 ]

															As Justice Stewart has observed:

															"[T]he exclusionary rule is not designed to serve a specific
deterrence function; that is, it is not designed to punish the
particular police officer for violating a person's fourth amendment
rights. Instead, the rule is designed to produce a 'systematic
deterrence:' the exclusionary rule is intended to create an
incentive for law enforcement officials to establish procedures by
which police officers are trained to comply with the fourth
amendment because the purpose of the criminal justice system --
bringing criminals to justice -- can be achieved only when evidence
of guilt may be used against defendants."

															Stewart, 83 Colum.L.Rev. at 1400. See also Oaks,
Studying the Exclusionary Rule in Search and Seizure, 37
U.Chi.L.Rev. 665, 709-710 (1970) ("The exclusionary rule is not
aimed at special deterrence, since it does not impose any direct
punishment on a law enforcement official who has broken the rule. .
. . The exclusionary rule is aimed at affecting the wider audience
of all law enforcement officials and society at large. It is meant
to discourage violations by individuals who have never experienced
any sanction for them"); Mertens & Wasserstrom, 70 Geo.L.J. at
399-401; Kamisar, 16 Creighton L.Rev. at 597, n. 204.

															[ Footnote 2/13 ]

															Although specific empirical data on the systemic deterrent
effect of the rule are not conclusive, the testimony of those
actually involved in law enforcement suggests that, at the very
least, the Mapp decision had the effect of increasing
police awareness of Fourth Amendment requirements and of prompting
prosecutors and police commanders to work towards educating
rank-and-file officers. For example, as former New York Police
Commissioner Murphy explained the impact of the Mapp decision:

															"I can think of no decision in recent times in the field of law
enforcement which had such a dramatic and traumatic effect. . . . I
was immediately caught up in the entire program of reevaluating our
procedures, which had followed the Defore rule, and
modifying, amending, and creating new policies and new instructions
for the implementation of Mapp. . . . Retraining sessions
had to be held from the very top administrators down to each of the
thousands of foot patrolmen."

															Murphy, Judicial Review of Police Methods in Law Enforcement:
The Problem of Compliance by Police Departments, 44 Texas L.Rev.
939, 941 (1966).

															Further testimony about the impact of the Mapp decision
can be found in the statement of Deputy Commissioner Reisman:

															"The Mapp case was a shock to us. We had to reorganize
our thinking, frankly. Before this, nobody bothered to take out
search warrants. Although the U.S. Constitution requires warrants
in most cases, the U.S. Supreme Court had ruled that evidence
obtained without a warrant -- illegally, if you will--was
admissible in state courts. So the feeling was, why bother? Well,
once that rule was changed, we knew we had better start teaching
our men about it."

															N.Y. Times, Apr. 28, 1965, p. 50, col. 1. A former United States
Attorney and now Attorney General of Maryland, Stephen Sachs, has
described the impact of the rule on police practices in similar
terms:

															"I have watched the rule deter, routinely, throughout my years
as a prosecutor. . . . [P]olice-prosecutor consultation is
customary in all our cases when Fourth Amendment concerns arise. .
. . In at least three Maryland jurisdictions, for example,
prosecutors are on twenty-four hour call to field search and
seizure questions presented by police officers."

															Sachs, The Exclusionary Rule: A Prosecutor's Defense, 1 Crim.
Justice Ethics 28, 30 (Summer/Fall 1982). See also LaFave,
The Fourth Amendment in an Imperfect World: On Drawing "Bright
Lines" and "Good Faith," 43 U.Pitt.L.Rev. 307, 319 (1982); Mertens
& Wasserstrom, supra, at 394-401.

															[ Footnote 2/14 ]

															The authors of a recent study of the warrant process in seven
cities concluded that application of a good faith exception where
an officer relies upon a warrant

															"would further encourage police officers to seek out the less
inquisitive magistrates and to rely on boilerplate formulae,
thereby lessening the value of search warrants overall.
Consequently, the benefits of adoption of a broad good faith
exception in terms of a few additional prosecutions appears to be
outweighed by the harm to the quality of the entire search warrant
process and the criminal justice system in general."

															R. Van Duizend, L. Sutton, & C. Carter, The Search Warrant
Process: Preconceptions, Perceptions, and Practices 8-12 (Review
Draft, National Center for State Courts, 1983). See also Stewart, 83 Colum.L.Rev. at 1403.

															[ Footnote 2/15 ]

															Just last Term, in Illinois v. Gates, 462 U.
S. 213 (1983), the Court noted:

															"Sufficient information must be presented to the magistrate to
allow that official to determine probable cause; his action cannot
be a mere ratification of the bare conclusions of others. In order
to ensure that such an abdication of the magistrate's duty does not
occur, courts must continue to conscientiously review the
sufficiency of affidavits on which warrants are issued." Id. at 462 U. S. 239 .
After today's decisions, there will be little reason for reviewing
courts to conduct such a conscientious review; rather, these courts
will be more likely to focus simply on the question of police good
faith. Despite the Court's confident prediction that such review
will continue to be conducted, see ante at 468 U. S.
924 -925, it is difficult to believe that busy courts
faced with heavy dockets will take the time to render essentially
advisory opinions concerning the constitutionality of the
magistrate's decision before considering the officer's good
faith.

															[ Footnote 2/16 ]

															As the Court of Appeals for the Second Circuit has observed in
this regard:

															"If a magistrate's issuance of a warrant were to be, as the
government would have it, an all but conclusive determination of
the validity of the search and of the admissibility of the evidence
seized thereby, police officers might have a substantial incentive
to submit their warrant applications to the least demanding
magistrates, since, once the warrant was issued, it would be
exceedingly difficult later to exclude any evidence seized in the
resulting search even if the warrant was issued without probable
cause. . . . For practical purposes, therefore, the standard of
probable cause might be diluted to that required by the least
demanding official authorized to issue warrants, even if this fell
well below what the Fourth Amendment required." United States v. Karathanos, 53 F.2d 26, 34 (1976).

															[ Footnote 2/17 ] See Kamisar, Gates, "Probable Cause," "Good
Faith," and Beyond, 69 Iowa L.Rev. 551, 588-589 (1984);
Wasserstrom, The Incredible Shrinking Fourth Amendment, 21
Am.Crim.L.Rev. 257 (1984); LaFave, 43 U.Pitt.L.Rev. at 307.

															JUSTICE STEVENS, concurring in the judgment in No. 82963, post, p. 468 U. S. 981 , and
dissenting in No. 82-1771.

															It is appropriate to begin with the plain language of the Fourth
Amendment:

															"The right of the people to be secure in their persons, houses,
papers, and effects, against unreasonable searches and seizures,
shall not be violated; and no Warrants shall issue but upon
probable cause, supported by Oath or affirmation, and particularly
describing the place to be searched, and the persons or things to
be seized."

															The Court assumes that the searches in these cases violated the
Fourth Amendment, yet refuses to apply the exclusionary rule
because the Court concludes that it was "reasonable" for the police
to conduct them. In my opinion, an official search and seizure
cannot be both "unreasonable" and "reasonable" at the same time.
The doctrinal vice in the Court's holding is its failure to
consider the separate purposes of the two prohibitory Clauses in
the Fourth Amendment. The first Clause prohibits unreasonable
searches and seizures, and the second prohibits the issuance of
warrants that are not supported by probable cause or that do not
particularly describe the place to be searched and the persons or
things to be seized. We have, of course, repeatedly held that
warrantless searches are presumptively unreasonable, [ Footnote 3/1 ] Page 468 U. S. 961 and that there are only a few carefully delineated exceptions to
that basic presumption. [ Footnote
3/2 ] But when such an exception has been recognized,
analytically we have necessarily concluded that the warrantless
activity was not "unreasonable" within the meaning of the first
Clause. Thus, any Fourth Amendment case may present two separate
questions: whether the search was conducted pursuant to a warrant
issued in accordance with the second Clause, and, if not, whether
it was nevertheless "reasonable" within the meaning of the first.
On these questions, the constitutional text requires that we speak
with one voice. We cannot intelligibly assume, arguendo, that a search was constitutionally unreasonable but that the seized
evidence is admissible because the same search was reasonable. I In No. 82-963, the Supreme Judicial Court of Massachusetts
determined that a warrant which purported to authorize a search of
respondent's home had been issued in violation of the Warrant
Clause. In its haste to make new law, this Court does not tarry to
consider this holding. Yet, as I will demonstrate, this holding is
clearly wrong; I would reverse the judgment on that ground
alone.

															In No. 82-1771, there is also a substantial question whether the
warrant complied with the Fourth Amendment. There was a strong
dissent on the probable cause issue when Leon was before
the Court of Appeals, and that dissent has been given added force
by this Court's intervening decision in Illinois v. Gates, 462 U. S. 213 (1983), which constituted a significant development in the law. It
is probable, though admittedly not certain, that the Court of
Appeals would now conclude that the warrant in Leon satisfied the Fourth Amendment if it were given the opportunity to
reconsider the issue in the light of Gates. Adherence to
our normal Page 468 U. S. 962 practice following the announcement of a new rule would
therefore postpone, and probably obviate, the need for the
promulgation of the broad new rule the Court announces today.
[ Footnote 3/3 ]

															It is, of course, disturbing that the Court chooses one case in
which there was no violation of the Fourth Amendment, and another
in which there is grave doubt on the question, in order to
promulgate a "good faith" exception to the Fourth Amendment's
exclusionary rule. The Court's explanation for its failure to
decide the merits of the Fourth Amendment question in No. 82-963 is
that it "is a fact-bound issue of little importance," Massachusetts v. Sheppard, post at 468 U. S. 988 ,
n. 5. In No. 82-1771, the Court acknowledges that the case could be
remanded to the Court of Appeals for reconsideration in light of Gates, yet does not bother to explain why it fails to do
so except to note that it is "within our power" to decide the
broader question in the case. United States v. Leon, ante at 468 U. S. 905 .
The Court seems determined to decide these cases on the broadest
possible grounds; such determination is utterly at odds with the
Court's traditional practice, as well as any principled notion of
judicial restraint. Decisions made in this manner are unlikely to
withstand the test of time.

															Judges, more than most, should understand the value of adherence
to settled procedures. By adopting a set of fair procedures, and
then adhering to them, courts of law ensure that justice is
administered with an even hand.

															"These are subtle matters, for they concern the ingredients of
what constitutes justice. Therefore, justice must satisfy the
appearance of justice." Offutt v. United States, 348 U. S.
11 , 348 U. S. 14 (1954). Of course, this Court has a duty to face questions of
constitutional law when necessary to the disposition of an actual
case or controversy. Marbury v.
Madison , 1 Cranch Page 468 U. S. 963 137, 5 U. S. 177 (1803). But when the Court goes beyond what is necessary to decide
the case before it, it can only encourage the perception that it is
pursuing its own notions of wise social policy, rather than
adhering to its judicial role. I do not believe the Court should
reach out to decide what is undoubtedly a profound question
concerning the administration of criminal justice before assuring
itself that this question is actually and of necessity presented by
the concrete facts before the Court. Although it may appear that
the Court's broad holding will serve the public interest in
enforcing obedience to the rule of law, for my part, I remain
firmly convinced that "the preservation of order in our communities
will be best ensured by adherence to established and respected
procedures." Groppi v. Leslie, 436 F.2d 331, 336 (CA7
1971) (en banc) (Stevens, J., dissenting), rev'd, 404 U. S. 496 (1972). II In No. 82-963, there is no contention that the police officers
did not receive appropriate judicial authorization for their search
of respondent's residence. A neutral and detached judicial officer
had correctly determined that there was probable cause to conduct a
search. Nevertheless, the Supreme Judicial Court suppressed the
fruits of the search because the warrant did not particularly
describe the place to be searched and the things to be seized.

															The particularity requirement of the Fourth Amendment has a
manifest purpose -- to prevent general searches. By limiting the
authorization to search to the specific areas and things for which
there is probable cause to search, the requirement ensures that the
search is carefully tailored to its justification, and does not
resemble the wide-ranging general searches that the Framers
intended to prohibit. [ Footnote
3/4 ] In this Page 468 U. S. 964 case the warrant did not come close to authorizing a general
search. [ Footnote 3/5 ]

															The affidavit supporting the application for the warrant
correctly identified the things to be seized, and on its face the
affidavit indicated that it had been presented to the judge who had
issued the warrant. [ Footnote 3/6 ]
Both the police officers and the judge were fully aware of the
contents of the affidavit, and therefore knew precisely what the
officers were authorized to search for. Since the affidavit was
available for after-the-fact review, the Massachusetts courts could
readily ascertain the limits of the officers' authority under the
warrant. In short, the judge who issued the warrant, the police
officers who executed it, and the reviewing courts all were able
easily to ascertain the precise scope of the authorization provided
by the warrant.

															All that our cases require is that a warrant contain a
description sufficient to enable the officers who execute it to
ascertain with reasonable effort where they are to search and what
they are to seize. [ Footnote 3/7 ]
The test is whether the executing officers' discretion has been
limited in a way that forbids a general search. [ Footnote 3/8 ] Here there was no question that
the Page 468 U. S. 965 executing officers' discretion had been limited -- they, as well
as the reviewing courts, knew the precise limits of their
authorization. There was simply no "occasion or opportunity for
officers to rummage at large," Zurcher v. Stanford Daily, 436 U. S. 547 , 436 U. S. 566 (1978). [ Footnote 3/9 ]

															The only Fourth Amendment interest that is arguably implicated
by the "defect" in the warrant is the citizen's interest in being
able to ascertain the limits of the officers' authorization by
examining the warrant. [ Footnote
3/10 ] Respondent, however, was not home at the time the warrant
was executed, and therefore had no occasion to see the warrant. The
two persons who were present when the warrant was executed,
respondent's mother and sister, did not read the warrant or ask to
have it read.

															"[T]he general rule [is] that Fourth Amendment rights are
personal rights which, like some other constitutional rights, may
not be vicariously asserted." Alderman v. United States, 394 U.
S. 165 , 394 U. S. 174 (1969). Thus, respondent, who has standing to assert only his own
Fourth Amendment interests, [ Footnote
3/11 ] cannot complain that his interest in ascertaining the
limits of the officers' authority under the search warrant was
infringed. [ Footnote 3/12 ] In
short, our Page 468 U. S. 966 precedents construing the particularity requirement of the
Warrant Clause unambiguously demonstrate that this warrant did not
violate the Fourth Amendment. III Even if it be assumed that there was a technical violation of
the particularity requirement in No. 82-963, it by no means follows
that the "warrantless" search in that case was "unreasonable"
within the meaning of the Fourth Amendment. For this search posed
none of the dangers to which the Fourth Amendment is addressed. It
was justified by a neutral magistrate's determination of probable
cause, and created no risk of a general search. It was eminently
"reasonable."

															In No. 82-1771, however, the Government now admits -- at least
for the tactical purpose of achieving what it regards as a greater
benefit -- that the substance, as well as the letter, of the Fourth
Amendment was violated. The Court therefore assumes that the
warrant in that case was not supported by probable cause, but
refuses to suppress the evidence obtained thereby because it
considers the police conduct to satisfy a "newfangled"
nonconstitutional standard of reasonableness. [ Footnote 3/13 ] Yet if the Court's assumption is
correct -- if there was no probable cause -- it must follow that it
was "unreasonable" Page 468 U. S. 967 for the authorities to make unheralded entries into and searches
of private dwellings and automobiles. The Court's conclusion that
such searches undertaken without probable cause can nevertheless be
"reasonable" is totally without support in our Fourth Amendment
jurisprudence.

															Just last Term, the Court explained what probable cause to issue
a warrant means:

															"The task of the issuing magistrate is simply to make a
practical, common sense decision whether, given all the
circumstances set forth in the affidavit before him, including the
'veracity' and the 'basis of knowledge' of persons supplying
hearsay information, there is a fair probability that contraband or
evidence of a crime will be found in a particular place." Illinois v. Gates, 462 U.S. at 462 U. S. 238 .
Moreover, in evaluating the existence of probable cause, reviewing
courts must give substantial deference to the magistrate's
determination. [ Footnote 3/14 ] In
doubtful cases, the warrant Page 468 U. S. 968 should be sustained. [ Footnote
3/15 ] The judgment as to whether there is probable cause must
be made in a practical and nontechnical manner. [ Footnote 3/16 ] The probable cause standard
therefore gives law enforcement officers ample room to engage in
any reasonable law enforcement activity. What is more, the standard
has been familiar to the law enforcement profession for centuries.
[ Footnote 3/17 ] In an opinion
written in 1949, and endorsed by the Court last Term in Gates, we explained:

															"These long-prevailing standards seek to safeguard citizens from
rash and unreasonable interferences with privacy and from unfounded
charges of crime. They also seek to give fair leeway for enforcing
the law in the community's protection. Because many situations
which confront officers in the course of executing their duties are
more or less ambiguous, room must be allowed for some mistakes on
their part. But the mistakes must be those of reasonable men,
acting on facts leading sensibly to their conclusions of
probability. The rule of probable cause is a practical,
nontechnical conception affording the best compromise that has been
found for accommodating these often opposing interests. Requiring
more would unduly hamper law enforcement. To allow less would be to
leave law-abiding citizens at the mercy of the officers' whim or
caprice." Brinegar v. United States, 338 U.
S. 160 , 338 U. S.
176 .

															Thus, if the majority's assumption is correct, that even after
paying heavy deference to the magistrate's finding and resolving
all doubt in its favor, there is no probable cause here, then by
definition -- as a matter of constitutional law -- Page 468 U. S. 969 the officers' conduct was unreasonable. [ Footnote 3/18 ] The Court's own hypothesis is that there
was no fair likelihood that the officers would find evidence of a
crime, and hence there was no reasonable law enforcement
justification for their conduct. [ Footnote 3/19 ]

															The majority's contrary conclusion rests on the notion that it
must be reasonable for a police officer to rely on a magistrate's
finding. Until today, that has plainly not been the law; it has
been well settled that, even when a magistrate issues a warrant,
there is no guarantee that the ensuing search and seizure is
constitutionally reasonable. Law enforcement officers have long
been on notice that, despite the magistrate's decision, a warrant
will be invalidated if the officers did not provide sufficient
facts to enable the magistrate to evaluate the existence of
probable cause responsibly and independently. [ Footnote 3/20 ] Reviewing courts have always
inquired into whether the magistrate acted properly in issuing the
warrant -- not merely whether the officers acted properly in
executing it. See Jones v. United States, 362 U.
S. 257 , 362 U. S.
271 -272 (1960). [ Footnote
3/21 ] Indeed, just last Term, in Gates, after
noting Page 468 U. S. 970 that

															""the duty of a reviewing court is simply to ensure that the
magistrate had a substantial basis for conclud[ing]' that
probable cause existed,"" 462 U.S. at 462 U. S.
238 -239 (quoting Jones, 362 U.S. at 362 U. S.
271 ), the Court added:

															"Sufficient information must be presented to the magistrate to
allow that official to determine probable cause; his action cannot
be a mere ratification of the bare conclusions of others. In order
to ensure that such an abdication of the magistrate's duty does not
occur, courts must continue to conscientiously review the
sufficiency of affidavits on which warrants are issued."

															462 U.S. at 462 U. S. 239 .
[ Footnote 3/22 ]

															Thus, under our cases, it has never been "reasonable" for the
police to rely on the mere fact that a warrant has issued; the
police have always known that, if they fail to supply the
magistrate with sufficient information, the warrant will be held
invalid, and its fruits excluded. [ Footnote 3/23 ]

															The notion that a police officer's reliance on a magistrate's
warrant is automatically appropriate is one the Framers of Page 468 U. S. 971 the Fourth Amendment would have vehemently rejected. The precise
problem that the Amendment was intended to address was the
unreasonable issuance of warrants. As we have often observed,
the Amendment was actually motivated by the practice of issuing
general warrants -- warrants which did not satisfy the
particularity and probable cause requirements. [ Footnote 3/24 ] The resentments which led to the
Amendment were directed at the issuance of warrants unjustified by
particularized evidence of wrongdoing. [ Footnote 3/25 ] Those who sought to amend the
Constitution to include a Bill of Rights repeatedly voiced the view
that the evil which had to be addressed was the issuance of
warrants on insufficient evidence. [ Footnote 3/26 ] As Professor Taylor has written: Page 468 U. S. 972 "[O]ur constitutional fathers were not concerned about
warrantless searches, but about overreaching warrants. It is
perhaps too much to say that they feared the warrant more than the
search, but it is plain enough that the warrant was the prime
object of their concern. Far from looking at the warrant as a
protection against unreasonable searches, they saw it as an
authority for unreasonable and oppressive searches. . . ."

															T. Taylor, Two Studies in Constitutional Interpretation 41
(1969).

															In short, the Framers of the Fourth Amendment were deeply
suspicious of warrants; in their minds, the paradigm of an abusive
search was the execution of a warrant not based on probable cause.
The fact that colonial officers had magisterial authorization for
their conduct when they engaged in general searches surely did not
make their conduct "reasonable." The Court's view that it is
consistent with our Constitution to adopt a rule that it is
presumptively reasonable to rely on a defective warrant is the
product of constitutional amnesia. [ Footnote 3/27 ] IV In Brinegar, Justice Jackson, after observing that

															"[i]ndications are not wanting that Fourth Amendment freedoms
are tacitly marked as secondary rights, to be relegated to a
deferred position,"

															338 U.S. at 338 U. S. 180 (dissenting opinion), continued:

															"These, I protest, are not mere second-class rights, but belong
in the catalog of indispensable freedoms. Among deprivations of
rights, none is so effective in cowing a population, crushing the
spirit of the individual, and putting terror in every heart.
Uncontrolled search and Page 468 U. S. 973 seizure is one of the first and most effective weapons in the
arsenal of every arbitrary government. And one need only briefly to
have dwelt and worked among a people possessed of many admirable
qualities but deprived of these rights to know that the human
personality deteriorates and dignity and self-reliance disappear
where homes, persons and possessions are subject at any hour to
unheralded search and seizure by the police."

															" * * * *" "Only occasional and more flagrant abuses come to the attention
of the courts, and then only those where the search and seizure
yields incriminating evidence and the defendant is at least
sufficiently compromised to be indicted. If the officers raid a
home, an office, or stop and search an automobile but find nothing
incriminating, this invasion of the personal liberty of the
innocent too often finds no practical redress. There may be, and I
am convinced that there are, many unlawful searches of homes and
automobiles of innocent people which turn up nothing incriminating,
in which no arrest is made, about which courts do nothing, and
about which we never hear."

															"Courts can protect the innocent against such invasions only
indirectly and through the medium of excluding evidence obtained
against those who frequently are guilty. . . . So a search against
Brinegar's car must be regarded as a search of the car of
Everyman." Id. at 338 U. S.
180 -181. Justice Jackson's reference to his experience
at Nuremberg should remind us of the importance of considering the
consequences of today's decision for "Everyman."

															The exclusionary rule is designed to prevent violations of the
Fourth Amendment. [ Footnote
3/28 ]

															"Its purpose is to deter -- to compel Page 468 U. S. 974 respect for the constitutional guaranty in the only effectively
available way, by removing the incentive to disregard it." Elkins v. United States, 364 U.
S. 206 , 364 U. S. 217 (1960). [ Footnote 3/29 ] If the
police cannot use evidence obtained through warrants issued on less
than probable cause, they have less incentive to seek those
warrants, and magistrates have less incentive to issue them.

															Today's decisions do grave damage to that deterrent function.
Under the majority's new rule, even when the police know their
warrant application is probably insufficient, they retain an
incentive to submit it to a magistrate, on the chance that he may
take the bait. No longer must they hesitate and seek additional
evidence in doubtful cases. Thus, what we Page 468 U. S. 975 said two Terms ago about a rule that would prevent exclusion
except in cases in which the authorities violate well-settled law
applies fully to the rule the Court adopts today:

															"If, as the Government argues, all rulings resolving unsettled
Fourth Amendment questions should be nonretroactive, then, in close
cases, law enforcement officials would have little incentive to err
on the side of constitutional behavior. Official awareness of the
dubious constitutionality of a practice would be counterbalanced by
official certainty that, so long as the Fourth Amendment law in the
area remained unsettled, evidence obtained through the questionable
practice would be excluded only in the one case definitively
resolving the unsettled question. Failure to accord any retroactive effect to Fourth Amendment rulings would 'encourage
police or other courts to disregard the plain purport of our
decisions and to adopt a let's-wait-until-it's-decided
approach.'" United States v. Johnson, 457 U.
S. 537 , 457 U. S. 561 (1982) (emphasis in original) (footnote omitted) (quoting Desist v. United States, 394 U. S. 244 , 394 U. S. 277 (1969) (Fortas, J., dissenting)). [ Footnote 3/30 ]

															The Court is, of course, correct that the exclusionary rule
cannot deter when the authorities have no reason to know that their
conduct is unconstitutional. But when probable cause is lacking,
then by definition a reasonable person under the circumstances
would not believe there is a fair likelihood that a search will
produce evidence of a crime. Under such circumstances, well-trained
professionals must know that they are violating the Constitution.
The Court's approach -- Page 468 U. S. 976 which, in effect, encourages the police to seek a warrant even
if they know the existence of probable cause is doubtful -- can
only lead to an increased number of constitutional violations.

															Thus, the Court's creation of a double standard of
reasonableness inevitably must erode the deterrence rationale that
still supports the exclusionary rule. But we should not ignore the
way it tarnishes the role of the judiciary in enforcing the
Constitution. For the original rationale for the exclusionary rule
retains its force as well as its relevance:

															"The tendency of those who execute the criminal laws of the
country to obtain conviction by means of unlawful seizures . . .
should find no sanction in the judgments of the courts which are
charged at all times with the support of the Constitution and to
which people of all conditions have a right to appeal for the
maintenance of such fundamental rights." Weeks v. United States, 232 U.
S. 383 , 232 U. S. 392 (1914). [ Footnote 3/31 ] Thus,

															"Courts which sit under our Constitution cannot and will not be
made party to lawless invasions of the constitutional Page 468 U. S. 977 rights of citizens by permitting unhindered governmental use of
the fruits of such invasions. . . ." Terry v. Ohio, 392 U. S. 1 , 392 U. S. 13 (1968). [ Footnote 3/32 ] As the
Court correctly notes, [ Footnote
3/33 ] we have refused to apply the exclusionary rule to
collateral contexts in which its marginal efficacy is questionable;
until today, however, every time the police have violated the
applicable commands of the Fourth Amendment a court has been
prepared to vindicate that Amendment by preventing the use of
evidence so obtained in the prosecution's case in chief against
those whose rights have been violated. [ Footnote 3/34 ] Today, for the first time, this Court
holds that, although the Constitution has been violated, no court
should do anything about it at any time and in any proceeding.
[ Footnote 3/35 ] In my
judgment, Page 468 U. S. 978 the Constitution requires more. Courts simply cannot escape
their responsibility for redressing constitutional violations if
they admit evidence obtained through unreasonable searches and
seizures, since the entire point of police conduct that violates
the Fourth Amendment is to obtain evidence for use at trial. If
such evidence is admitted, then the courts become not merely the
final and necessary link in an unconstitutional chain of events,
but its actual motivating force.

															"If the existing code does not permit district attorneys to have
a hand in such dirty business, it does not permit the judge to
allow such iniquities to succeed." Olmstead v. United States, 277 U.
S. 438 , 277 U. S. 470 (1928) (Holmes, J., dissenting). Nor should we so easily concede
the existence of a constitutional violation for which there is no
remedy. [ Footnote 3/36 ] To do so
is to convert a Bill of Rights into an unenforced honor
code that the police may follow in their discretion. The
Constitution requires more; it requires a remedy. [ Footnote 3/37 ] If the Court's
new rule is to be followed, the Bill of Rights should be
renamed. Page 468 U. S. 979 It is, of course, true that the exclusionary rule exerts a high
price -- the loss of probative evidence of guilt. But that price is
one courts have often been required to pay to serve important
social goals. [ Footnote 3/38 ]
That price is also one the Fourth Amendment requires us to pay,
assuming as we must that the Framers intended that its strictures
"shall not be violated." For in all such cases, as Justice Stewart
has observed,

															"the same extremely relevant evidence would not have been
obtained had the police officer complied with the commands of the
fourth amendment in the first place. [ Footnote 3/39 ]"

															"[T]he forefathers thought this was not too great a price to pay
for that decent privacy of home, papers and effects which is
indispensable to individual dignity and self-respect. They may have
overvalued privacy, but I am not disposed to set their command at
naught." Harris v. United States, 331 U.
S. 145 , 331 U. S. 198 (1947) (Jackson, J., dissenting). [ Footnote 3/40 ]

															We could, of course, facilitate the process of administering
justice to those who violate the criminal laws by ignoring the
commands of the Fourth Amendment -- indeed, by ignoring Page 468 U. S. 980 the entire Bill of Rights -- but it is the very purpose of a
Bill of Rights to identify values that may not be sacrificed to
expediency. In a just society, those who govern, as well as those
who are governed, must obey the law.

															While I concur in the Court's judgment in No. 82-963, I would
vacate the judgment in No. 82-1771 and remand the case to the Court
of Appeals for reconsideration in the light of Gates. Accordingly, I respectfully dissent from the disposition in No.
82-1771.

															[ Footnote 3/1 ] See, e.g., Payton v. New York, 445 U.
S. 573 , 445 U. S. 586 (1980); Chimel v. California, 395 U.
S. 752 , 395 U. S.
762 -763 (1969).

															[ Footnote 3/2 ] See, e.g., Coolidge v. New Hampshire, 403 U.
S. 443 , 403 U. S.
474 -475 (1971); Vale v. Louisiana, 399 U. S.
30 (1970).

															[ Footnote 3/3 ]

															In his petition for certiorari in Leon, the Solicitor
General did not seek plenary review, but only that the petition "be
disposed of as appropriate in light of the Court's decision in Illinois v. Gates, " Pet. for Cert. in United States v.
Leon, No. 82-1771, p. 10.

															[ Footnote 3/4 ] See Andresen v. Maryland, 427 U.
S. 463 , 427 U. S. 480 (1976); Stanley v. Georgia, 394 U.
S. 557 , 394 U. S.
569 -572 (1969) (Stewart, J., concurring in result); Stanford v. Texas, 379 U. S. 476 , 379 U. S.
481 -482, 485 (1965); Go-Bart Importing Co. v. United
States, 282 U. S. 344 , 282 U. S. 357 (1931); Marron v. United States, 275 U.
S. 192 , 275 U. S.
195 -196 (1927).

															[ Footnote 3/5 ]

															Indeed, the "defect" in the warrant was that it authorized --
albeit mistakenly -- a search for quite particular "things to be
seized," controlled substances, rather than the evidence described
in the affidavit supporting the warrant application. This "defect"
posed no risk of a general search. On its face, the warrant
correctly identified the place to be searched. Thus, the threshold
invasion of privacy -- entry into respondent's home -- was properly
and specifically authorized. Moreover, the four corners of the
warrant plainly indicate that it was not intended to authorize a
search for controlled substances. On the cover of the warrant the
caption "Controlled Substances" had been crossed out, and an
"addendum" to the warrant authorized a search for and seizure of a
rifle and ammunition, indicating that the warrant was not limited
to controlled substances.

															[ Footnote 3/6 ]

															The issuing judge attested to the affiant's signature on the
affidavit.

															[ Footnote 3/7 ] See Steele v. United States, 267 U.
S. 498 , 267 U. S. 503 (1925).

															[ Footnote 3/8 ] See Lo-Ji Sales, Inc. v. New York, 442 U.
S. 319 , 442 U. S. 325 (1979); Andresen v. Maryland, 427 U.S. at 427 U. S.
480 -482; Marcus v. Search Warrant, 367 U.
S. 717 , 367 U. S.
732 -733 (1961).

															[ Footnote 3/9 ] See also Coolidge v. New Hampshire, 403 U.S. at 403 U. S.
467 .

															[ Footnote 3/10 ] See Illinois v. Gates, 462 U.
S. 213 , 462 U. S. 236 (1983); United States v. Chadwick, 433 U. S.
1 , 433 U. S. 9 (1977); Camara v. Municipal Court, 387 U.
S. 523 , 387 U. S. 532 (1967).

															[ Footnote 3/11 ] See, e.g., Rawlings v. Kentucky, 448 U. S.
98 , 448 U. S.
104 -106 (1980); Rakas v. Illinois, 439 U.
S. 128 (1978).

															[ Footnote 3/12 ]

															Even if respondent had standing to assert his right to be able
to ascertain the officers' authority from the four corners of the
warrant, it is doubtful that he could succeed. On its face, the
warrant authorized a search of respondent's residence, "42 Deckard
Street." Had respondent read the warrant, he would have had no
reason to question the officers' right to enter the premises.
Moreover, the face of the warrant indicated that the caption
"Controlled Substances" had been stricken, and at the bottom of the
warrant an addendum authorized the search for and seizure of a
rifle and ammunition. The supporting affidavit, which the police
had with them when they executed the warrant, and which was
attested by the same judge who had issued the warrant, described in
detail the items which the police were authorized to search for and
to seize.

															[ Footnote 3/13 ]

															I borrow the adjective from Justice Clark, who so characterized
the warrants authorized by the Court in Camara v. Municipal
Court, 387 U. S. 523 (1967), but not authorized by the Constitution itself. In an
opinion joined by Justice Harlan and Justice Stewart, he wrote:

															"Today the Court renders this municipal experience, which dates
back to Colonial days, for naught by overruling Frank v.
Maryland [ 359 U.S.
360 (1959)] and by striking down hundreds of city ordinances
throughout the country and jeopardizing thereby the health,
welfare, and safety of literally millions of people."

															"But this is not all. It prostitutes the command of the Fourth
Amendment that 'no Warrants shall issue, but upon probable cause'
and sets up in the health and safety codes area inspection a
newfangled 'warrant' system that is entirely foreign to Fourth
Amendment standards. It is regrettable that the Court wipes out
such a long and widely accepted practice and creates in its place
such enormous confusion in all of our towns and metropolitan cities
in one fell swoop." See v. City of Seattle, 387 U.
S. 541 , 387 U. S. 547 (1967) (dissenting in both Camara and See ).

															The kind of doctrinal difficulties in the two lines of cases
engendered by the Court's creation of a newfangled warrant, compare Marshall v. Barlow's, Inc., 436 U.
S. 307 (1978), with Donovan v. Dewey, 452 U. S. 594 (1981), can be expected to grow out of the Court's creation of a
new double standard of reasonableness today. Ironically, as I have
previously suggested, the failure to consider both Clauses of the
Amendment infects both lines of decision. See Michigan v.
Clifford, 464 U. S. 287 , 464 U. S.
301 -303 (1984) (STEVENS, J., concurring in judgment); Dewey, 452 U.S. at 452 U. S.
606 -608 (STEVENS, J., concurring); Michigan v.
Tyler, 436 U. S. 499 , 436 U. S. 513 (1978) (STEVENS, J., concurring in part and concurring in
judgment); Barlow's, 436 U.S. at 436 U. S.
325 -339 (STEVENS J., dissenting).

															[ Footnote 3/14 ] See Massachusetts v. Upton, 466 U.
S. 727 , 466 U. S.
732 -733 (1984) (per curiam); Illinois v. Gates, 462 U.S. at 462 U. S. 236 ; United States v. Harris, 403 U. S. 573 , 403 U. S.
577 -583 (1971) (plurality opinion); Spinelli v.
United States, 393 U. S. 410 , 393 U. S. 419 (1969); Aguilar v. Texas, 378 U.
S. 108 , 378 U. S. 111 (1964); Jones v. United States, 362 U.
S. 257 , 362 U. S. 271 (1960).

															[ Footnote 3/15 ] See Illinois v. Gates, 462 U.S. at 462 U. S. 237 ,
n. 10; United States v. Ventresca, 380 U.
S. 102 , 380 U. S. 109 (1965).

															[ Footnote 3/16 ] See Massachusetts v. Upton, 466 U.S. at 466 U. S. 732 (per curiam); Illinois v. Gates, 462 U.S. at 462 U. S. 231 ; United States v. Ventresca, 380 U.S. at 380 U. S.
108 .

															[ Footnote 3/17 ] See, e.g., 2 M. Hale, Pleas of the Crown 150 (1st Am.
ed. 1847).

															[ Footnote 3/18 ]

															"[I]f nothing said under oath in the warrant application
demonstrates the need for an unannounced search by force, the
probable cause requirement is not satisfied. In the absence of some
other showing of reasonableness, the ensuing search violates the
Fourth Amendment." Zurcher v. Stanford Daily, 436 U.
S. 547 , 436 U. S. 583 (1978) (STEVENS, J., dissenting).

															[ Footnote 3/19 ]

															As the majority recognizes, United States v. Leon, ante at 468 U. S. 915 ,
n. 13, an officer's good faith cannot make otherwise "unreasonable"
conduct reasonable. See Terry v. Ohio, 392 U. S.
1 , 392 U. S. 22 (1968); Beck v. Ohio, 379 U. S. 89 , 379 U. S. 97 (1964); Henry v. United States, 361 U. S.
98 , 361 U. S. 102 (1959). The majority's failure to appreciate the significance of
that recognition is inexplicable.

															[ Footnote 3/20 ] See Franks v. Delaware, 438 U.
S. 154 , 438 U. S. 165 , 438 U. S.
169 -170 (1978), Whiteley v. Warden, 401 U. S. 560 , 401 U. S. 564 (1971); Spinelli v. United States, 393 U.S. at 393 U. S.
415 -416; United States v. Ventresca, 380 U.S.
at 380 U. S.
108 -109; Aguilar v. Texas, 378 U.S. at 378 U. S.
113 -115; Nathanson v. United States, 290 U. S. 41 (1933); Byars v. United States, 273 U. S.
28 (1927).

															[ Footnote 3/21 ]

															In making this point in Franks v. Delaware, 438 U. S. 154 (1978), JUSTICE BLACKMUN wrote for the Court:

															"We see no principled basis for distinguishing between the
question of the sufficiency of an affidavit, which is also subject
to a post-search examination, and the question of its
integrity." Id. at 438 U. S. 171 .
Yet today the Court justifies its holding in part by distinguishing
veracity claims, United States v. Leon, ante at 468 U. S.
922 -923, thereby distinguishing what we previously held
could not be distinguished on a principled basis. Just why it
should be less reasonable for an innocent officer to rely on a
warrant obtained by another officer's fraud than for him to rely on
a warrant that is not supported by probable cause is entirely
unclear to me.

															[ Footnote 3/22 ]

															Judicial review of magisterial determinations is all the more
necessary since the magistrate acts without benefit of adversarial
presentation; his determination partakes of the unreliability
inherent in any ex parte proceeding. See Franks v.
Delaware, 438 U.S. at 438 U. S. 169 .

															[ Footnote 3/23 ]

															The majority seems to be captivated by a vision of courts
invalidating perfectly reasonable police conduct because of
"technical" violations of the Fourth Amendment. In my view, there
is no such thing as a "technical" violation of the Fourth
Amendment. No search or seizure can be unconstitutional unless it
is "unreasonable." By definition, a Fourth Amendment violation
cannot be reasonable. My analysis of No. 82-963 illustrates this
point.

															[ Footnote 3/24 ] See, e.g., Steagald v. United States, 451 U.
S. 204 , 451 U. S. 220 (1981); Payton v. New York, 445 U.S. at 445 U. S.
583 -584; Lo-Ji Sales, Inc. v. New York, 442
U.S. at 442 U. S. 325 ; Marshall v. Barlow's, Inc., 436 U.S. at 436 U. S.
327 -328 (STEVENS, J., dissenting); United States v.
Chadwick, 433 U.S. at 433
U. S. 7 -8; Chimel v. California, 395 U.S. at 395 U. S.
760 -762; Stanford v. Texas, 379 U.S. at 379 U. S.
480 -485; Marcus v. Search Warrant, 367 U.S. at 367 U. S.
727 -729; Henry v. United States, 361 U.S. at 361 U. S.
100 -101; Frank v. Maryland, 359 U.
S. 360 , 359 U. S.
363 -365 (1959); United States v. Rabinowitz, 339 U. S. 56 , 339 U. S. 69 -70
(1950) (Frankfurter, J., dissenting); Marron v. United
States, 275 U.S. at 275 U. S.
195 -196; Weeks v. United States, 232 U.
S. 383 , 232 U. S.
390 -391 (1914); Boyd v. United States, 116 U. S. 616 , 116 U. S.
624 -630 (1886).

															[ Footnote 3/25 ] See J. Landynski, Search and Seizure and the Supreme
Court 19-47 (1966); N. Lasson, The History and Development of the
Fourth Amendment to the United States Constitution 53-98 (1937); R.
Rutland, The Birth of the Bill of Rights 11 (rev. ed.1983); Marke,
The Writs of Assistance Case and the Fourth Amendment, in Essays in
Legal History in Honor of Felix Frankfurter 351 (M. Forkosch
ed.1966).

															[ Footnote 3/26 ] See 1 The Bill of Rights: A Documentary History 473,
488-489, 508 (B. Schwartz ed.1971); 2 id. at 658, 665,
730, 733-734, 805-806, 815, 841-842, 913, 968. In fact, the
original version of the Fourth Amendment contained only one clause
providing that the right to be protected against unreasonable
searches and seizures "shall not be violated by warrants issuing. .
. ." The change to its present form broadened the coverage of the
Amendment, but did not qualify the unequivocal prohibition against
the issuance of warrants without probable cause. See 2 id. at 1112; N. Lasson, supra, 468
U.S. 897 fn3/25|>n. 25, at 101-103.

															[ Footnote 3/27 ]

															"It makes all the difference in the world whether one recognizes
the central fact about the Fourth Amendment, namely, that it was a
safeguard against recurrence of abuses so deeply felt by the
Colonies as to be one of the potent causes of the Revolution, or
one thinks of it as merely a requirement for a piece of paper." United States v. Rabinowitz, 339 U.S. at 339 U. S. 69 (Frankfurter, J., dissenting).

															[ Footnote 3/28 ]

															For at least two reasons, the exclusionary rule is a better
remedy than a civil action against an offending officer. Unlike the
fear of personal liability, it should not create excessive
deterrence; moreover, it avoids the obvious unfairness of
subjecting the dedicated officer to the risk of monetary liability
for a misstep while endeavoring to enforce the law. Society, rather
than the individual officer, should accept the responsibility for
inadequate training or supervision of officers engaged in hazardous
police work. What THE CHIEF JUSTICE wrote, some two decades ago,
remains true today:

															"It is the proud claim of a democratic society that the people
are masters and all officials of the state are servants of the
people. That being so, the ancient rule of respondeat
superior furnishes us with a simple, direct and reasonable
basis for refusing to admit evidence secured in violation of
constitutional or statutory provisions. Since the policeman is
society's servant, his acts in the execution of his duty are
attributable to the master or employer. Society as a whole is thus
responsible, and society is 'penalized' by refusing it the benefit
of evidence secured by the illegal action. This satisfies me more
than the other explanations because it seems to me that society --
in a country like ours -- is involved in and is responsible for
what is done in its name and by its agents. Unlike the Germans of
the 1930's and early '40's, we cannot say 'it is all The Leader's
doing. I am not responsible.' In a representative democracy, we are
responsible, whether we like it or not. And so each of us is
involved and each is in this sense responsible when a police
officer breaks rules of law established for our common
protection."

															Burger, Who Will Watch the Watchman?, 14 Am.U.L.Rev. 1, 14
(1964) (emphasis in original) (footnote omitted).

															[ Footnote 3/29 ] See Stone v. Powell, 428 U. S. 465 , 428 U. S. 484 (1976); United States v. Janis, 428 U.
S. 433 , 428 U. S. 443 ,
n. 12 (1976); United States v. Calandra, 414 U.
S. 338 , 414 U. S.
347 -348 (1974); Terry v. Ohio, 392 U.S. at 392 U. S. 29 ; Tehan v. United States ex rel. Shott, 382 U.
S. 406 , 382 U. S. 413 (1966); Mapp v. Ohio, 367 U. S. 643 , 367 U. S. 656 (1961).

															[ Footnote 3/30 ] See also LaFave, The Fourth Amendment in an Imperfect
World: On Drawing "Bright Lines" and "Good Faith," 43 U.Pitt.L.Rev.
307, 358 (1982); Stewart, The Road to Mapp v. Ohio and
Beyond: The Origins, Development and Future of the Exclusionary
Rule in Search and Seizure Cases, 83 Colum.L.Rev. 1365, 1401-1403
(1983); Wasserstrom, The Incredible Shrinking Fourth Amendment, 21
Am.Crim.L.Rev. 257, 395-397(1984).

															[ Footnote 3/31 ]

															The Court continued:

															"The efforts of the courts and their officials to bring the
guilty to punishment, praiseworthy as they are, are not to be aided
by the sacrifice of those great principles established by years of
endeavor and suffering which have resulted in their embodiment in
the fundamental law of the land. The United States Marshal could
only have invaded the house of the accused when armed with a
warrant issued as required by the Constitution, upon sworn
information and describing with reasonable particularity the things
for which the search was to be made. Instead, he acted without
sanction of law, doubtless prompted by the desire to bring further
proof to the aid of the Government, and, under color of his office,
undertook to make a seizure of private papers in direct violation
of the constitutional prohibition against such action. Under such
circumstances, without sworn information and particular
description, not even an order of court would have justified such
procedure. . . . To sanction such proceedings would be to affirm by
judicial decision a manifest neglect, if not an open defiance, of
the prohibitions of the Constitution, intended for the protection
of the people against such unauthorized action."

															232 U.S. at 232 U. S.
393 -394.

															[ Footnote 3/32 ] See United States v. Peltier, 422 U.
S. 531 , 422 U. S. 536 (1975); Lee v. Florida, 392 U. S. 378 , 392 U. S.
385 -386 (1968); Berger v. New York, 388 U. S. 41 , 388 U. S. 50 (1967); Mapp v. Ohio, 367 U.S. at 367 U. S.
647 -650; Byars v. United States, 273 U.S. at 273 U. S.
33 -34.

															[ Footnote 3/33 ] United States v. Leon, ante at 468 U. S.
908 -913.

															[ Footnote 3/34 ]

															Indeed, we have concluded that judicial integrity is not
compromised by the refusal to apply the exclusionary rule to
collateral contexts precisely because the defendant is able to
vindicate his rights in the primary context -- his trial and direct
appeal therefrom. See Stone v. Powell, 428 U.S. at 428 U. S.
485 -486.

															[ Footnote 3/35 ]

															As the majority recognizes, United States v. Leon, ante at 468 U. S.
922 -923, and n. 23, in all cases in which its "good
faith" exception to the exclusionary rule would operate, there will
also be immunity from civil damages. See also United States v.
Ross, 456 U. S. 798 , 456 U. S. 823 ,
n. 32 (1982); Stadium Films, Inc. v. Baillargeon, 542 F.2d
577, 578 (CA1 1976); Madison v. Maner, 441 F.2d 537 (CA1
1971). See generally Pierson v. Ray, 386 U.
S. 547 (1967). The Court amazingly suggests that, in
some cases in which suppression would not be appropriate, courts
should nevertheless adjudicate the merits of Fourth Amendment
claims to provide guidance to police and magistrates, but not a
remedy. United States v. Leon, ante at 468 U. S. 925 .
Not only is the propriety of deciding constitutional questions in
the absence of the strict necessity to do so open to serious
question, see Bowen . United States, 422 U.
S. 916 , 422 U. S. 920 (1975), but such a proceeding, in which a court would declare that
the Constitution had been violated but that it was unwilling to do
anything about it, seems almost a mockery:

															"[T]he assurance against unreasonable federal searches and
seizures would be 'a form of words,' valueless and undeserving of
mention in a perpetual charter of inestimable human liberties." Mapp v. Ohio, 367 U.S. at 367 U. S. 655 . See also Segura v. United States, ante at 468 U. S.
838 -840 (STEVENS, J., dissenting).

															[ Footnote 3/36 ]

															"The very essence of civil liberty certainly consists in the
right of every individual to claim the protection of the laws,
whenever he receives an injury." Marbury v.
Madison , 1 Cranch 137, 5 U. S. 163 (1803). See generally Schrock & Welsh, Up From Calandra: The Exclusionary Rule as a Constitutional
Requirement, 59 Minn.L.Rev. 251, 350-372 (1974).

															[ Footnote 3/37 ] See Stewart, 83 Colum.L.Rev. at 1383-1384 (footnotes
omitted) ("In my opinion, however, the framers did not intend the
Bill of Rights to be no more than unenforceable guiding principles
-- no more than a code of ethics under an honor system. The
proscriptions and guarantees in the amendments were intended to
create legal rights and duties"). See also Ervin, The
Exclusionary Rule: An Essential Ingredient of the Fourth Amendment,
1983 S.Ct.Rev. 283. In fact, if the Constitution of the United
States does not compel use of the exclusionary rule, Mapp v.
Ohio, 367 U. S. 643 (1961), which the majority does not purport to question, could not
have been decided as it was. See id. at 367 U. S. 655 ("We hold that all evidence obtained by searches and seizures in
violation of the Constitution is, by that same authority,
inadmissible in a state court").

															[ Footnote 3/38 ]

															The exclusion of probative evidence in order to serve some other
policy is by no means unique to the Fourth Amendment. In his famous
treatise on evidence, Dean Wigmore devoted an entire volume to such
exclusionary rules, which are common in the law of evidence. See 8 J. Wigmore, Evidence (J. McNaughton rev.1961)
(discussing, inter alia, marital privilege,
attorney-client privilege, communications among jurors, state
secrets privilege, physician-patient privilege, priest-penitent
privilege).

															[ Footnote 3/39 ]

															Stewart, 83 Colum.L.Rev. at 1392 (footnote omitted). See
also Traynor, Mapp v. Ohio at Large in the Fifty
States, 1962 Duke L.J. 319, 322 ("Ah, but surely the guilty should
not go free? However grave the question, it seemed improperly
directed at the exclusionary rule. The hard answer is in the United
States Constitution, as well as in state constitutions. They make
it clear that the guilty would go free if the evidence necessary to
convict could only have been obtained illegally, just as they would
go free if such evidence were lacking because the police had
observed the constitutional restraints upon them").

															[ Footnote 3/40 ] See also United States v. Di Re, 332 U.
S. 581 , 332 U. S. 595 (1948).