OCTOBER TERM, 1999

															Syllabus

															ILLINOIS v. WARDLOW

															CERTIORARI TO THE SUPREME COURT OF ILLINOIS

															No. 98-1036. Argued November 2, 1999-Decided January 12,2000

															Respondent Wardlow fled upon seeing a caravan of police vehicles
converge on an area of Chicago known for heavy narcotics
trafficking. When Officers Nolan and Harvey caught up with him on
the street, Nolan stopped him and conducted a protective patdown
search for weapons because in his experience there were usually
weapons in the vicinity of narcotics transactions. Discovering a
handgun, the officers arrested Wardlow. The Illinois trial court
denied his motion to suppress, finding the gun was recovered during
a lawful stop and frisk. He was convicted of unlawful use of a
weapon by a felon. In reversing, the State Appellate Court found
that Nolan did not have reasonable suspicion to make the stop under Terry v. Ohio, 392 U. S. 1 . The State
Supreme Court affirmed, determining that sudden flight in a high
crime area does not create a reasonable suspicion justifying a Terry stop because flight may simply be an exercise of the
right to "go on one's way," see Florida v. Royer, 460 U. S.
491 . Held: The officers' actions did not violate the Fourth
Amendment. This case, involving a brief encounter between a citizen
and a police officer on a public street, is governed by Terry, under which an officer who has a reasonable,
articulable suspicion that criminal activity is afoot may conduct a
brief, investigatory stop. While "reasonable suspicion" is a less
demanding standard than probable cause, there must be at least a
minimal level of objective justification for the stop. An
individual's presence in a "high crime area," standing alone, is
not enough to support a reasonable, particularized suspicion of
criminal activity, but a location's characteristics are relevant in
determining whether the circumstances are sufficiently suspicious
to warrant further investigation, Adams v. Williams, 407 U. S.
143 ,144,147-148. In this case, moreover, it was also Wardlow's
unprovoked flight that aroused the officers' suspicion. Nervous,
evasive behavior is another pertinent factor in determining
reasonable suspicion, e. g., United States v. Brignoni-Ponce, 422 U. S. 873, 885, and headlong flight is
the consummate act of evasion. In reviewing the propriety of an
officer's conduct, courts do not have available empirical studies
dealing with inferences from suspicious behavior, and this Court
cannot reasonably demand scientific certainty when none exists.
Thus, the reasonable suspicion determination must be based on
commonsense judgments and inferences about human behavior. See 120 Syllabus United States v. Cortez, 449 U. S. 411 ,418.
Officer Nolan was justified in suspecting that Wardlow was involved
in criminal activity, and, therefore, in investigating further.
Such a holding is consistent with the decision in Florida v. Royer, supra, at 498, that an individual, when approached,
has a right to ignore the police and go about his business.
Unprovoked flight is the exact opposite of "going about one's
business." While flight is not necessarily indicative of ongoing
criminal activity, Terry recognized that officers can detain
individuals to resolve ambiguities in their conduct, 392 U. S., at
30, and thus accepts the risk that officers may stop innocent
people. If they do not learn facts rising to the level of probable
cause, an individual must be allowed to go on his way. But in this
case the officers found that Wardlow possessed a handgun and
arrested him for violating a state law. The propriety of that
arrest is not before the Court. pp. 123-126.

															183 Ill. 2d 306, 701 N. E. 2d 484, reversed and remanded.

															REHNQUIST, C. J., delivered the opinion of the Court, in which
O'CONNOR, SCALIA, KENNEDY, and THOMAS, JJ., joined. STEVENS, J.,
filed an opinion concurring in part and dissenting in part, in
which SOUTER, GINSBURG, and BREYER, JJ., joined, post, p.
126.

															Richard A. Devine argued the cause for petitioner. With him on
the briefs were James E. Ryan, Attorney General of Illinois, Joel
D. Bertocchi, Solicitor General, Renee G. Goldfarb, Theodore Fotios
Burtzos, and Veronica Ximena Calderon.

															Malcolm L. Stewart argued the cause for the United States as
amicus curiae urging reversal. With him on the brief were Solicitor
General Waxman, Assistant Attorney General Robinson, Deputy
Solicitor General Dreeben, and Deborah Watson. James B. Koch argued the cause for respondent. With him
on the brief were Lynn N. Weisberg and Thomas G. Gardiner. *

															*Briefs of amici curiae urging reversal were filed for
the State of Ohio et al. by Betty D. Montgomery, Attorney
General of Ohio, Edward B. Foley, State Solicitor, Robert C. Maier and Alejandro Almaguer, Assistant Solicitors, and Thomas R. Keller, Acting Attorney
General of Hawaii, and by the Attorneys General for their
respective States as follows: Bill Pryor of Alabama, Ken
Salazar of Colorado, M. Jane Brady of Delaware, 121 CHIEF JUSTICE REHNQUIST delivered the opinion of the Court.

															Respondent Wardlow fled upon seeing police officers patrolling
an area known for heavy narcotics trafficking. Two of the officers
caught up with him, stopped him, and conducted a protective patdown
search for weapons. Discovering a .38-caliber handgun, the officers
arrested Wardlow. We hold that the officers' stop did not violate
the Fourth Amendment to the United States Constitution.

															On September 9, 1995, Officers Nolan and Harvey were working as
uniformed officers in the special operations section of the Chicago
Police Department. The officers were driving the last car of a
four-car caravan converging on an area known for heavy narcotics
trafficking in order to investigate drug transactions. The officers
were traveling together because they expected to find a crowd of
people in the area, including lookouts and customers.

															As the caravan passed 4035 West Van Buren, Officer Nolan
observed respondent Wardlow standing next to the building Alan G. Lance of Idaho, Carla J. Stovall of Kansas, Richard P. Ieyoub of Louisiana, Mike Hatch of Minnesota, Michael C. Moore of
Mississippi, Don Stenberg of Nebraska, Frankie Sue Del
Papa of Nevada, Michael P. Easley of North Carolina, W A. Drew Edmondson of Oklahoma, Charles M. Condon of
South Carolina, Mark L. Barnett of South Dakota, and Mark
L. Earley of Virginia; for the Wayne County Prosecuting
Attorney by John D. O'Hair, pro se, Timothy A. Baughman, and Jeffrey Caminsky; for Americans for Effective Law
Enforcement, Inc., et al. by Wayne W Schmidt, James P.
Manak, and Richard Weintraub; for the Criminal Justice
Legal Foundation by Kent S. Scheidegger and Charles L. Hobson; and for the National Association of
Police Organizations et al. by Stephen R. McSpadden. Briefs of amici curiae urging affirmance were filed for the
American Civil Liberties Union et al. by Tracey Maclin, Steven R.
Shapiro, Harvey Grossman, and Barbara E. Bergman; for the NAACP
Legal Defense & Educational Fund, Inc., by Elaine R. Jones,
Theodore M. Shaw, George H. Kendall, and Laura E. Hankins; and for
the Rutherford Institute by John W Whitehead and Steven H.
Aden. 122 holding an opaque bag. Respondent looked in the direction of the
officers and fled. Nolan and Harvey turned their car southbound,
watched him as he ran through the gangway and an alley, and
eventually cornered him on the street. Nolan then exited his car
and stopped respondent. He immediately conducted a protective
patdown search for weapons because in his experience it was common
for there to be weapons in the near vicinity of narcotics
transactions. During the frisk, Officer Nolan squeezed the bag
respondent was carrying and felt a heavy, hard object similar to
the shape of a gun. The officer then opened the bag and discovered
a .38-caliber handgun with five live rounds of ammunition. The
officers arrested Wardlow.

															The Illinois trial court denied respondent's motion to suppress,
finding the gun was recovered during a lawful stop and frisk. App.
14. Following a stipulated bench trial, Wardlow was convicted of
unlawful use of a weapon by a felon. The Illinois Appellate Court
reversed Wardlow's conviction, concluding that the gun should have
been suppressed because Officer Nolan did not have reasonable
suspicion sufficient to justify an investigative stop pursuant to Terry v. Ohio, 392 U. S. 1 (1968). 287
Ill. App. 3d 367, 678 N. E. 2d 65 (1997).

															The Illinois Supreme Court agreed. 183 Ill. 2d 306, 701 N. E. 2d
484 (1998). While rejecting the Appellate Court's conclusion that
Wardlow was not in a high crime area, the Illinois Supreme Court
determined that sudden flight in such an area does not create a
reasonable suspicion justifying a Terry stop. 183 Ill. 2d,
at 310, 701 N. E. 2d, at 486. Relying on Florida v. Royer, 460 U.
S. 491 (1983), the court explained that although police have
the right to approach individuals and ask questions, the individual
has no obligation to respond. The person may decline to answer and
simply go on his or her way, and the refusal to respond, alone,
does not provide a legitimate basis for an investigative stop. 183
Ill. 123 2d, at 311-312, 701 N. E. 2d, at 486-487. The court then
determined that flight may simply be an exercise of this right to
"go on one's way," and, thus, could not constitute reasonable
suspicion justifying a Terry stop. 183 Ill. 2d, at 312, 701
N. E. 2d, at 487.

															The Illinois Supreme Court also rejected the argument that
flight combined with the fact that it occurred in a high crime area
supported a finding of reasonable suspicion because the "high crime
area" factor was not sufficient standing alone to justify a Terry stop. Finding no independently suspicious
circumstances to support an investigatory detention, the court held
that the stop and subsequent arrest violated the Fourth Amendment.
We granted certiorari, 526 U. S. 1097 (1999), and now reverse.1

															This case, involving a brief encounter between a citizen and a
police officer on a public street, is governed by the analysis we
first applied in Terry. In Terry, we held that an
officer may, consistent with the Fourth Amendment, conduct a brief,
investigatory stop when the officer has a reasonable, articulable
suspicion that criminal activity is afoot. 392 U. S., at 30. While
"reasonable suspicion" is a less demanding standard than probable
cause and requires a showing considerably less than preponderance
of the evidence, the Fourth Amendment requires at least a minimal
level of objective justification for making the stop. United
States v. Sokolow, 490 U. S. 1 , 7 (1989). The
officer must be able

															1 The state courts have differed on whether unprovoked flight is
sufficient grounds to constitute reasonable suspicion. See, e.
g., State v. Anderson, 155 Wis. 2d 77, 454 N. W. 2d 763
(1990) (flight alone is sufficient); Platt v. State, 589 N. E. 2d 222 (Ind. 1992) (same); Harris v. State, 205 Ga. App. 813,423 S. E. 2d 723 (1992) (flight in high crime area
sufficient); State v. Hicks, 241 Neb. 357, 488 N. W.
2d 359 (1992) (flight is not enough); State v. Tucker, 136 N. J. 158, 642 A. 2d 401 (1994) (same); People v. Shabaz, 424 Mich. 42, 378 N. W. 2d 451
(1985) (same); People v. Wilson, 784 P. 2d 325 (Colo.
1989) (same). 124 to articulate more than an "inchoate and unparticularized
suspicion or 'hunch'" of criminal activity. Terry, supra, at
27.2

															Nolan and Harvey were among eight officers in a four-car caravan
that was converging on an area known for heavy narcotics
trafficking, and the officers anticipated encountering a large
number of people in the area, including drug customers and
individuals serving as lookouts. App.8. It was in this context that
Officer Nolan decided to investigate Wardlow after observing him
flee. An individual's presence in an area of expected criminal
activity, standing alone, is not enough to support a reasonable,
particularized suspicion that the person is committing a crime. Brown v. Texas, 443 U. S. 47 (1979). But
officers are not required to ignore the relevant characteristics of
a location in determining whether the circumstances are
sufficiently suspicious to warrant further investigation.
Accordingly, we have previously noted the fact that the stop
occurred in a "high crime area" among the relevant contextual
considerations in a Terry analysis. Adams v. Williams, 407
U. S. 143 , 144, 147-148 (1972).

															In this case, moreover, it was not merely respondent's presence
in an area of heavy narcotics trafficking that aroused the
officers' suspicion, but his unprovoked flight upon noticing the
police. Our cases have also recognized that nervous, evasive
behavior is a pertinent factor in determining reasonable suspicion. United States v. Brignoni-Ponce, 422 U. S. 873 , 885
(1975); Florida v. Rodriguez, 469 U. S. 1 , 6 (1984) (per curiam); United States v. Sokolow,
supra, at 8-9. Headlong flight-wherever it occurs-is the
consummate act of evasion: It is not necessarily indicative of
wrongdoing, but it is certainly suggestive of such. In reviewing
the propriety of an officer's conduct, courts do not have available
empirical studies dealing with inferences drawn from suspicious

															2We granted certiorari solely on the question whether the
initial stop was supported by reasonable suspicion. Therefore, we
express no opinion as to the lawfulness of the frisk independently
of the stop. 125 behavior, and we cannot reasonably demand scientific certainty
from judges or law enforcement officers where none exists. Thus,
the determination of reasonable suspicion must be based on
commonsense judgments and inferences about human behavior. See United States v. Cortez, 449 U. S. 411, 418 (1981).
We conclude Officer Nolan was justified in suspecting that Wardlow
was involved in criminal activity, and, therefore, in investigating
further.

															Such a holding is entirely consistent with our decision in Florida v. Royer, 460 U. S. 491 (1983),
where we held that when an officer, without reasonable suspicion or
probable cause, approaches an individual, the individual has a
right to ignore the police and go about his business. Id., at 498. And any "refusal to cooperate, without more, does not
furnish the minimal level of objective justification needed for a
detention or seizure." Florida v. Bostick, 501 U. S. 429 , 437
(1991). But unprovoked flight is simply not a mere refusal to
cooperate. Flight, by its very nature, is not "going about one's
business"; in fact, it is just the opposite. Allowing officers
confronted with such flight to stop the fugitive and investigate
further is quite consistent with the individual's right to go about
his business or to stay put and remain silent in the face of police
questioning.

															Respondent and amici also argue that there are innocent
reasons for flight from police and that, therefore, flight is not
necessarily indicative of ongoing criminal activity. This fact is
undoubtedly true, but does not establish a violation of the Fourth
Amendment. Even in Terry, the conduct justifying the stop
was ambiguous and susceptible of an innocent explanation. The
officer observed two individuals pacing back and forth in front of
a store, peering into the window and periodically conferring. 392
U. S., at 5-6. All of this conduct was by itself lawful, but it
also suggested that the individuals were casing the store for a
planned robbery. Terry recognized that the officers could
detain the individuals to resolve the ambiguity. Id., at
30. 126 Opinion of STEVENS, J.

															In allowing such detentions, Terry accepts the risk that
officers may stop innocent people. Indeed, the Fourth Amendment
accepts that risk in connection with more drastic police action;
persons arrested and detained on probable cause to believe they
have committed a crime may turn out to be innocent. The Terry stop is a far more minimal intrusion, simply allowing
the officer to briefly investigate further. If the officer does not
learn facts rising to the level of probable cause, the individual
must be allowed to go on his way. But in this case the officers
found respondent in possession of a handgun, and arrested him for
violation of an Illinois firearms statute. No question of the
propriety of the arrest itself is before us.

															The judgment of the Supreme Court of Illinois is reversed, and
the cause is remanded for further proceedings not inconsistent with
this opinion.

															It is so ordered.

															JUSTICE STEVENS, with whom JUSTICE SOUTER, JUSTICE GINSBURG, and
JUSTICE BREYER join, concurring in part and dissenting in part.

															The State of Illinois asks this Court to announce a "bright-line
rule" authorizing the temporary detention of anyone who flees at
the mere sight of a police officer. Brief for Petitioner 7-36.
Respondent counters by asking us to adopt the opposite per
se rule-that the fact that a person flees upon seeing the
police can never, by itself, be sufficient to justify a temporary
investigative stop of the kind authorized by Terry v. Ohio, 392 U. S.
1 (1968). Brief for Respondent 6-31.

															The Court today wisely endorses neither per se rule.
Instead, it rejects the proposition that "flight is ... necessarily
indicative of ongoing criminal activity," ante, at 125,
adhering to the view that "[t]he concept of reasonable suspicion
... is not readily, or even usefully, reduced to a neat set of
legal rules," but must be determined by looking to "the 127 totality of the circumstances-the whole picture," United
States v. Sokolow, 490 U. S. 1 , 7-8 (1989)
(internal quotation marks and citation omitted). Abiding by this
framework, the Court concludes that "Officer Nolan was justified in
suspecting that Wardlow was involved in criminal activity." Ante, at 125.

															Although I agree with the Court's rejection of the per se rules proffered by the parties, unlike the Court, I am persuaded
that in this case the brief testimony of the officer who seized
respondent does not justify the conclusion that he had reasonable
suspicion to make the stop. Before discussing the specific facts of
this case, I shall comment on the parties' requests for a per
se rule.

															I

															In Terry v. Ohio, we first recognized "that a
police officer may in appropriate circumstances and in an
appropriate manner approach a person for purposes of investigating
possibly criminal behavior even though there is no probable cause
to make an arrest," 392 U. S., at 22, an authority permitting the
officer to "stop and briefly detain a person for investigative
purposes," Sokolow, 490 U. S., at 7. We approved as well "a
reasonable search for weapons for the protection of the police
officer, where he has reason to believe that he is dealing with an
armed and dangerous individual, regardless of whether he has
probable cause to arrest the individual for a crime." Terry, 392 U. S., at 27. Cognizant that such police intrusion had never
before received constitutional imprimatur on less than probable
cause, id., at 11-12, 20, we reflected upon the magnitude of
the departure we were endorsing. "Even a limited search," we said,
"constitutes a severe, though brief, intrusion upon cherished
personal security, and it must be an annoying, frightening, and
perhaps humiliating experience." Id., at 24-25.1

															1 We added that a Terry frisk "is a serious intrusion
upon the sanctity of the person, which may inflict great indignity
and arouse strong resentment, and is not to be undertaken lightly."
392 U. S., at 17. The resent- 128 Opinion of STEVENS, J.

															Accordingly, we recognized only a "narrowly drawn authority"
that is "limited to that which is necessary for the discovery of
weapons." Id., at 27, 26. An officer conducting an
investigatory stop, we further explained, must articulate "a
particularized and objective basis for suspecting the particular
person stopped of criminal activity." United States v. Cortez, 449 U.
S. 411 , 417-418 (1981). That determination, we admonished,
"becomes meaningful only when it is assured that at some point the
conduct of those charged with enforcing the laws can be subjected
to the more detached, neutral scrutiny of a judge who must evaluate
the reasonableness of a particular search or seizure in light of
the particular circumstances." Terry, 392 U. S., at 21. In
undertaking that neutral scrutiny "based on all of the
circumstances," a court relies on "certain commonsense conclusions
about human behavior." Cortez, 449 U. S., at 418; see also ante, at 125. "[T]he relevant inquiry" concerning the
inferences and conclusions a court draws "is not whether particular
conduct is 'innocent' or 'guilty,' but the degree of suspicion that
attaches to particular types of noncriminal acts." Sokolow, 490 U. S., at 10.

															The question in this case concerns "the degree of suspicion that
attaches to" a person's flight-or, more precisely, what
"commonsense conclusions" can be drawn respecting the motives
behind that flight. A pedestrian may break into a run for a variety
of reasons-to catch up with a friend a block or two away, to seek
shelter from an impending storm, to arrive at a bus stop before the
bus leaves, to get home in time for

															ment engendered by that intrusion is aggravated, not mitigated,
if the officer's entire justification for the stop is the belief
that the individual is simply trying to avoid contact with the
police or move from one place to another-as he or she has a right
to do (and do rapidly). See Chicago v. Morales, 527 U. S. 41 , 53
(1999) (plurality opinion) ("We have expressly identified this
'right to remove from one place to another according to
inclination' as 'an attribute of personal liberty' protected by the
Constitution" (citation omitted)); Florida v. Bostick, 501
U. S. 429 , 437 (1991); Florida v. Royer, 460 U. S. 491 , 497-498
(1983) (plurality opinion); Terry, 392 U. S., at 32-33
(Harlan, J., concurring); see also ante, at 125. 129 dinner, to resume jogging after a pause for rest, to avoid
contact with a bore or a bully, or simply to answer the call of
nature-any of which might coincide with the arrival of an officer
in the vicinity. A pedestrian might also run because he or she has
just sighted one or more police officers. In the latter instance,
the State properly points out "that the fleeing person may be, inter alia, (1) an escapee from jail; (2) wanted on a
warrant; (3) in possession of contraband, (i. e. drugs, weapons,
stolen goods, etc.); or (4) someone who has just committed another
type of crime." Brief for Petitioner 9, n. 4.2 In short, there are
unquestionably circumstances in which a person's flight is
suspicious, and undeniably instances in which a person runs for
entirely innocent reasons.3

															Given the diversity and frequency of possible motivations for
flight, it would be profoundly unwise to endorse either per
se rule. The inference we can reasonably draw about the
motivation for a person's flight, rather, will depend on a number
of different circumstances. Factors such as the time of day, the
number of people in the area, the character of the neighborhood,
whether the officer was in uniform, the way the runner was dressed,
the direction and speed of the

															2 If the fleeing person exercises his or her right to remain
silent after being stopped, only in the third of the State's four
hypothetical categories is the stop likely to lead to probable
cause to make an arrest. And even in the third category, flight
does not necessarily indicate that the officer is "dealing with an
armed and dangerous individual." Terry v. Ohio,
392 3 Compare, e. g., Proverbs 28:1 ("The wicked flee
when no man pursueth: but the righteous are as bold as a lion")
with Proverbs 22:3 ("A shrewd man sees trouble coming and lies low;
the simple walk into it and pay the penalty").

															I have rejected reliance on the former proverb in the past,
because its "ivory-towered analysis of the real world" fails to
account for the experiences of many citizens of this country,
particularly those who are minorities. See California v. Hodari D., 499
U. S. 621 , 630, n. 4 (1991) (STEVENS, J., dissenting). That
this pithy expression fails to capture the total reality of our
world, however, does not mean it is inaccurate in all
instances. 130 Opinion of STEVENS, J.

															flight, and whether the person's behavior was otherwise unusual
might be relevant in specific cases. This number of variables is
surely sufficient to preclude either a bright-line rule that always
justifies, or that never justifies, an investigative stop based on
the sole fact that flight began after a police officer appeared
nearby.4

															Still, Illinois presses for a per se rule regarding
"unprovoked flight upon seeing a clearly identifiable police
officer." Id., at 7. The phrase "upon seeing," as used by
Illinois, apparently assumes that the flight is motivated by the
presence of the police officer. 5 Illinois contends that unprovoked
flight is "an extreme reaction," id., at 8, because innocent
people simply do not "flee at the mere sight of the police," id., at 24. To be sure, Illinois concedes, an innocent
person-even one distrustful of the police-might "avoid eye contact
or even sneer at the sight of an officer," and that

															4 Of course, Terry itself recognized that sometimes
behavior giving rise to reasonable suspicion is entirely innocent,
but it accepted the risk that officers may stop innocent people.
392 U. S., at 30. And as the Court correctly observes, it is
"undoubtedly true" that innocent explanations for flight exist, but
they do not "establish a violation of the Fourth Amendment." Ante, at 125. It is equally true, however, that the innocent
explanations make the single act of flight sufficiently ambiguous
to preclude the adoption of a per se rule.

															In Terry, furthermore, reasonable suspicion was supported
by a concatenation of acts, each innocent when viewed in isolation,
that when considered collectively amounted to extremely suspicious
behavior. See 392 U. S., at 5-7, 22-23. Flight alone, however, is
not at all like a "series of acts, each of them perhaps innocent in
itself, but which taken together warran[t] further investigation." Id., at 22. Nor is flight similar to evidence which in the
aggregate provides "fact on fact and clue on clue afford[ing] a
basis for the deductions and inferences," supporting reasonable
suspicion. United States v. Cortez, 449 U. S. 411 , 419
(1981).

															5 Nowhere in Illinois' briefs does it specify what it means by
"unprovoked." At oral argument, Illinois explained that if officers
precipitate a flight by threats of violence, that flight is
"provoked." But if police officers in a patrol car-with lights
flashing and siren sounding-descend upon an individual for the sole
purpose of seeing if he or she will run, the ensuing flight is
"unprovoked." Tr. of Oral Arg. 17-18,20. 131 would not justify a Terry stop or any sort of per
se inference. Id., at 8-9. But, Illinois insists,
unprovoked flight is altogether different. Such behavior is so
"aberrant" and "abnormal" that a per se inference is
justified. Id., at 8-9, and n.4.

															Even assuming we know that a person runs because he sees the
police, the inference to be drawn may still vary from case to case.
Flight to escape police detection, we have said, may have an
entirely innocent motivation: "[I]t is a matter of common knowledge that men who are entirely
innocent do sometimes fly from the scene of a crime through fear of
being apprehended as the guilty parties, or from an unwillingness
to appear as witnesses. Nor is it true as an accepted axiom of
criminal law that 'the wicked flee when no man pursueth, but the
righteous are as bold as a lion.' Innocent men sometimes hesitate
to confront a jury-not necessarily because they fear that the jury
will not protect them, but because they do not wish their names to
appear in connection with criminal acts, are humiliated at being
obliged to incur the popular odium of an arrest and trial, or
because they do not wish to be put to the annoyance or expense of
defending themselves." Alberty v. United States, 162 U. S. 499 ,
511 (1896). In addition to these concerns, a reasonable person may conclude
that an officer's sudden appearance indicates nearby criminal
activity. And where there is criminal activity there is also a
substantial element of danger-either from the criminal or from a
confrontation between the criminal and the police. These
considerations can lead to an innocent and understandable desire to
quit the vicinity with all speed.6

															6 Statistical studies of bystander victimization are rare. One
study attributes this to incomplete recordkeeping and a lack of
officially compiled data. See Sherman, Steele, Laufersweiler,
Hooper, & Julian, Stray Bul- 132 Opinion of STEVENS, J.

															Among some citizens, particularly minorities and those residing
in high crime areas, there is also the possibility that the fleeing
person is entirely innocent, but, with or without justification,
believes that contact with the police can itself be dangerous,
apart from any criminal activity associated with the officer's
sudden presence.7 For such a person,

															lets and "Mushrooms": Random Shootings of Bystanders in Four
Cities, 1977-1988,5 J. of Quantitative Criminology 297,303 (1989).
Nonetheless, that study, culling data from newspaper reports in
four large cities over an 11-year period, found "substantial
increases in reported bystander killings and woundings in all four
cities." Id., at 306. From 1986 to 1988, for example, the
study identified 250 people who were killed or wounded in bystander
shootings in the four survey cities. Id., at 306-311. Most
significantly for the purposes of the present case, the study found
that such incidents "rank at the top of public outrage." Id., at 299. The saliency of this phenomenon, in turn,
"violate[s] the routine assumptions" of day-to-day affairs, and,
"[w]ith enough frequency ... it shapes the conduct of daily life." Ibid. 7 See Johnson, Americans' Views on Crime and Law Enforcement:
Survey Findings, Nat. Institute of Justice J. 13 (Sept. 1997)
(reporting study by the Joint Center for Political and Economic
Studies in April 1996, which found that 43% of African-Americans
consider "police brutality and harassment of African-Americans a
serious problem" in their own community); President's Comm'n on Law
Enforcement and Administration of Justice, Task Force Report: The
Police 183-184 (1967) (documenting the belief, held by many
minorities, that field interrogations are conducted
"indiscriminately" and "in an abusive ... manner," and labeling
this phenomenon a "principal problem" causing "friction" between
minorities and the police) (cited in Terry, 392 U. S., at
14, n. 11); see also Casimir, Minority Men: We Are Frisk Targets,
N. Y. Daily News, Mar. 26,1999, p. 34 (informal survey of 100 young
black and Hispanic men living in New York City; 81 reported having
been stopped and frisked by police at least once; none of the 81
stops resulted in arrests); Brief for NAACP Legal Defense &
Educational Fund as Amicus Curiae 17-19 (reporting figures
on disproportionate street stops of minority residents in
Pittsburgh and Philadelphia, Pennsylvania, and St. Petersburg,
Florida); U. S. Dept. of Justice, Bureau of Justice Statistics, S.
Smith, Criminal Victimization and Perceptions of Community Safety
in 12 Cities 25 (June 1998) (African-American residents in 12
cities are more than twice as likely to be dissatisfied with police
practices than white residents in same community). 133 unprovoked flight is neither "aberrant" nor "abnormal." 8
Moreover, these concerns and fears are known to the police officers
themselves,9 and are validated by law enforcement investigations
into their own practices.10 Accordingly, the

															8 See, e. g., Kotlowitz, Hidden Casualties: Drug
War's Emphasis on Law Enforcement Takes a Toll on Police, Wall
Street Journal, Jan. 11, 1991, p. A2, col. 1 ("Black leaders
complained that innocent people were picked up in the drug sweeps
.... Some teen-agers were so scared of the task force they ran even
if they weren't selling drugs").

															Many stops never lead to an arrest, which further exacerbates
the perceptions of discrimination felt by racial minorities and
people living in high crime areas. See Goldberg, The Color of
Suspicion, N. Y. Times Magazine, June 20, 1999, p. 85 (reporting
that in 2-year period, New York City Police Department Street
Crimes Unit made 45,000 stops, only 9,500, or 20%, of which
resulted in arrest); Casimir, supra n. 7 (reporting that in
1997, New York City's Street Crimes Unit conducted 27,061
stop-andfrisks, only 4,647 of which, 17%, resulted in arrest). Even
if these data were race neutral, they would still indicate that
society as a whole is paying a significant cost in infringement on
liberty by these virtually random stops. See also n. 1, supra. 9 The Chief of the Washington, D. C., Metropolitan Police
Department, for example, confirmed that "sizeable percentages of
Americans todayespecially Americans of color-still view policing in
the United States to be discriminatory, if not by policy and
definition, certainly in its day-to-day application." P. Verniero,
Attorney General of New Jersey, Interim Report of the State Police
Review Team Regarding Allegations of Racial Profiling 46 (Apr. 20,
1999) (hereinafter Interim Report). And a recent survey of 650 Los
Angeles Police Department officers found that 25% felt that"
'racial bias (prejudice) on the part of officers toward minority
citizens currently exists and contributes to a negative interaction
between police and the community.''' Report of the Independent
Comm'n on the Los Angeles Police Department 69 (1991); see also 5
United States Comm'n on Civil Rights, Racial and Ethnic Tensions in
American Communities: Poverty, Inequality and Discrimination, The
Los Angeles Report 26 (June 1999).

															10 New Jersey's Attorney General, in a recent investigation into
allegations of racial profiling on the New Jersey Turnpike,
concluded that "minority motorists have been treated differently
[by New Jersey State Troopers] than non-minority motorists during
the course of traffic stops on the New Jersey Turnpike." "[T]he
problem of disparate treatment is real-not imagined," declared the
Attorney General. Not surprisingly, 134 Opinion of STEVENS, J.

															evidence supporting the reasonableness of these beliefs is too
pervasive to be dismissed as random or rare, and too persuasive to
be disparaged as inconclusive or insufficientY In

															the report concluded that this disparate treatment "engender[s]
feelings of fear, resentment, hostility, and mistrust by minority
citizens." See Interim Report 4, 7. Recently, the United States
Department of Justice, citing this very evidence, announced that it
would appoint an outside monitor to oversee the actions of the New
Jersey State Police and ensure that it enacts policy changes
advocated by the Interim Report, and keeps records on racial
statistics and traffic stops. See Kocieniewski, U. S. Will Monitor
New Jersey Police on Race Profiling, N. Y. Times, Dec. 23,
1999,

															Likewise, the Massachusetts Attorney General investigated
similar allegations of egregious police conduct toward minorities.
The report stated:

															"We conclude that Boston police officers engaged in improper,
and unconstitutional, conduct in the 1989-90 period with respect to
stops and searches of minority individuals .... Although we cannot
say with precision how widespread this illegal conduct was, we
believe that it was sufficiently common to justify changes in
certain Department practices.

															"Perhaps the most disturbing evidence was that the scope of a number of Terry searches went far beyond anything
authorized by that case and indeed, beyond anything that we believe
would be acceptable under the federal and state constitutions even
where probable cause existed to conduct a full search incident to
an arrest. Forcing young men to lower their trousers, or otherwise
searching inside their underwear, on public streets or in public
hallways, is so demeaning and invasive of fundamental precepts of
privacy that it can only be condemned in the strongest terms. The
fact that not only the young men themselves, but independent
witnesses complained of strip searches, should be deeply alarming
to all members of this community." J. Shannon, Attorney General of
Massachusetts, Report of the Attorney General's Civil Rights
Division on Boston Police Department Practices 60-61 (Dec. 18,
1990).

															11 Taking into account these and other innocent motivations for
unprovoked flight leads me to reject Illinois' requested per
se rule in favor of adhering to a totality-of-the-circumstances
test. This conclusion does not, as Illinois suggests, "establish a
separate Terry analysis based on the individual
characteristics of the person seized." Reply Brief for Petitioner
14. My rejection of a per se rule, of course, applies to
members of all races.

															It is true, as Illinois points out, that Terry approved
of the stop and frisk procedure notwithstanding "[t]he wholesale
harassment by certain 135 any event, just as we do not require "scientific certainty" for
our commonsense conclusion that unprovoked flight can sometimes
indicate suspicious motives, see ante, at 124-125, neither
do we require scientific certainty to conclude that unprovoked
flight can occur for other, innocent reasons.12

															The probative force of the inferences to be drawn from flight is
a function of the varied circumstances in which it occurs.
Sometimes those inferences are entirely consistent with the
presumption of innocence, sometimes they justify further
investigation, and sometimes they justify an immediate stop and
search for weapons. These considerations have led us to avoid
categorical rules concerning a person's flight and the presumptions
to be drawn therefrom: "Few things ... distinguish an enlightened system of judicature
from a rude and barbarous one more than the manner in which they
deal with evidence. The former weighs testimony, whilst the latter,
conscious perhaps of its inability to do so or careless of the
consequences of error, at times rejects whole portions en
masse, and at others converts pieces of evidence into rules of
law by investing with conclusive effect some whose probative force
has been found to be in general considerable .... Our ancestors,
observing that guilty persons usually fled from justice, adopted
the hasty conclusion that it was only the guilty who did so ... so
that under the old law, a man who fled to avoid being tried for
felony forfeited elements of the police community, of which minority groups,
particularly Negroes, frequently complain." 392 U. S., at 14. But
in this passage, Terry simply held that such concerns would
not preclude the use of the stop and frisk procedure altogether.
See id., at 17, n. 14. Nowhere did Terry suggest that
such concerns cannot inform a court's assessment of whether
reasonable suspicion sufficient to justify a particular stop
existed.

															12 As a general matter, local courts often have a keener and
more informed sense of local police practices and events that may
heighten these concerns at particular times or locations. Thus, a
reviewing court may accord substantial deference to a local court's
determination that fear of the police is especially acute in a
specific location or at a particular time. 136 Opinion of STEVENS, J. all his goods even though he were acquitted . In modern times
more correct views have prevailed, and the evasion of or flight
from justice seems now nearly reduced to its true place in the
administration of the criminal law, namely, that of a
circumstance-a fact which it is always of importance to take into
consideration, and combined with others may afford strong evidence
of guilt, but which, like any other piece of presumptive evidence,
it is equally absurd and dangerous to invest with infallibility." Hickory v. United States, 160 U. S. 408 , 419-420
(1896) (internal quotation marks omitted). "Unprovoked flight," in short, describes a category of activity
too broad and varied to permit a per se reasonable inference
regarding the motivation for the activity. While the innocent
explanations surely do not establish that the Fourth Amendment is
always violated whenever someone is stopped solely on the basis of
an unprovoked flight, neither do the suspicious motivations
establish that the Fourth Amendment is never violated when a Terry stop is predicated on that fact alone. For these
reasons, the Court is surely correct in refusing to embrace either per se rule advocated by the parties. The totality of the
circumstances, as always, must dictate the result.13

															13 Illinois' reliance on the common law as a conclusive answer
to the issue at hand is mistaken. The sources from which it gleans
guidance focus either on flightfollowing an accusation of criminal
activity, see 4 W. Blackstone, Commentaries *387 ("For flight
... on an accusation of treason, felony, or even petit larceny
... is an offence carrying with it a strong presumption of guilt"
(emphasis added in part)), or are less dogmatic than Illinois
contends, compare Brief for Petitioner 15 ("[A] person's flight was
considered ... conclusive proof of guilt") with A. Burrill,
Circumstantial Evidence 472 (1856) ("So impressed was the old
common law with considerations of this kind, that it laid down the
rule, which passed into a maxim,-that flight from justice was
equivalent to confession of guilt .... But this maxim ... was
undoubtedly expressed in too general and sweeping terms"). 137 II

															Guided by that totality-of-the-circumstances test, the Court
concludes that Officer Nolan had reasonable suspicion to stop
respondent. Ante, at 125. In this respect, my view differs
from the Court's. The entire justification for the stop is
articulated in the brief testimony of Officer Nolan. Some facts are
perfectly clear; others are not. This factual insufficiency leads
me to conclude that the Court's judgment is mistaken.

															Respondent Wardlow was arrested a few minutes after noon on
September 9, 1995. 183 Ill. 2d 306, 308, n. 1, 701 N. E. 2d 484,
485, n. 1 (1998).14 Nolan was part of an eightofficer, four-car
caravan patrol team. The officers were headed for "one of the areas
in the 11th District [of Chicago] that's high [in] narcotics
traffic." App. 8.15 The reason why four cars were in the caravan
was that "[n]ormally in these different areas there's an enormous
amount of people, sometimes lookouts, customers." Ibid. Officer Nolan testified that he was in uniform on that day, but he
did not recall whether he was driving a marked or an unmarked car. Id., at 4.

															Officer Nolan and his partner were in the last of the four
patrol cars that "were all caravaning eastbound down Van Buren." Id., at 8. Nolan first observed respondent "in front of 4035
West Van Buren." Id., at 7. Wardlow "looked in our direction
and began fleeing." Id., at 9. Nolan then "began driving
southbound down the street observing [respondent] running through
the gangway and the alley southbound," and observed that Wardlow
was carrying a white,

															14 At the suppression hearing, the State failed to present
testimony as to the time of respondent's arrest. The Illinois
Supreme Court, however, took notice of the time recorded in Officer
Nolan's arrest report. See 183 Ill. 2d, at 308, n. 1, 701 N. E. 2d,
at 485, n. 1.

															15 The population of the 11th district is over 98,000 people.
See Brief for the National Association of Police Organizations et
al. as Amici Curiae App. II. 138 Opinion of STEVENS, J.

															opaque bag under his arm. Id., at 6, 9. After the car
turned south and intercepted respondent as he "ran right towards
us," Officer Nolan stopped him and conducted a "protective search,"
which revealed that the bag under respondent's arm contained a
loaded handgun. Id., at 9-11.

															This terse testimony is most noticeable for what it fails to
reveal. Though asked whether he was in a marked or unmarked car,
Officer Nolan could not recall the answer. Id., at 4. He was
not asked whether any of the other three cars in the caravan were
marked, or whether any of the other seven officers were in uniform.
Though he explained that the size of the caravan was because
"[n]ormally in these different areas there's an enormous amount of
people, sometimes lookouts, customers," Officer Nolan did not
testify as to whether anyone besides Wardlow was nearby 4035
West Van Buren. Nor is it clear that that address was the intended
destination of the caravan. As the Appellate Court of Illinois
interpreted the record, "it appears that the officers were simply
driving by, on their way to some unidentified location, when they
noticed defendant standing at 4035 West Van Buren." 287 Ill. App.
3d 367, 370-371, 678 N. E. 2d 65, 67 (1997).16 Officer Nolan's
testimony also does not reveal how fast the officers were driving.
It does not indicate whether he saw respondent notice the other
patrol cars. And it does not say whether the caravan, or any part
of it, had already passed Wardlow by before he began to run.

															Indeed, the Appellate Court thought the record was even "too
vague to support the inference that ... defendant's flight was
related to his expectation of police focus on him." Id., at
371, 678 N. E. 2d, at 67. Presumably, respondent did not react to
the first three cars, and we cannot even be sure that he recognized
the occupants of the fourth as police officers. The adverse
inference is based entirely on the officer's

															16 Of course, it would be a different case if the officers had
credible information respecting that specific street address which
reasonably led them to believe that criminal activity was afoot in
that narrowly defined area. 139 statement: "He looked in our direction and began fleeing."
App.9.17

															No other factors sufficiently support a finding of reasonable
suspicion. Though respondent was carrying a white, opaque bag under
his arm, there is nothing at all suspicious about that. Certainly
the time of day-shortly after noondoes not support Illinois'
argument. Nor were the officers "responding to any call or report
of suspicious activity in the area." 183 Ill. 2d, at 315, 701 N. E.
2d, at 488. Officer Nolan did testify that he expected to find "an
enormous amount of people," including drug customers or lookouts,
App. 8, and the Court points out that "[i]t was in this context
that Officer Nolan decided to investigate Wardlow after observing
him flee," ante, at 124. This observation, in my view, lends
insufficient weight to the reasonable suspicion analysis; indeed,
in light of the absence of testimony that anyone else was nearby
when respondent began to run, this observation points in the
opposite direction.

															The State, along with the majority of the Court, relies as well
on the assumption that this flight occurred in a high crime area.
Even if that assumption is accurate, it is insufficient because
even in a high crime neighborhood unprovoked flight does not
invariably lead to reasonable suspicion. On the contrary, because
many factors providing innocent motivations for unprovoked flight
are concentrated in high crime areas, the character of the
neighborhood arguably makes an inference of guilt less appropriate,
rather than more so. Like unprovoked flight itself, presence in a
high crime neighborhood is a fact too generic and susceptible to
innocent explanation to satisfy the reasonable suspicion inquiry.
See Brown v. Texas, 443 U. S. 47 , 52 (1979);
see also n. 15, supra. 17 Officer Nolan also testified that respondent "was looking at us," App. 5 (emphasis added), though this minor
clarification hardly seems sufficient to support the adverse
inference. 140 Opinion of STEVENS, J.

															It is the State's burden to articulate facts sufficient to
support reasonable suspicion. Brown v. Texas, 443 U.
S., at 52; see also Florida v. Royer, 460 U. S. 491 , 500 (1983)
(plurality opinion). In my judgment, Illinois has failed to
discharge that burden. I am not persuaded that the mere fact that
someone standing on a sidewalk looked in the direction of a passing
car before starting to run is sufficient to justify a forcible stop
and frisk.

															I therefore respectfully dissent from the Court's judgment to
reverse the court below.


OCTOBER TERM, 1996

															Syllabus

															RICHARDS v. WISCONSIN

															CERTIORARI TO THE SUPREME COURT OF WISCONSIN No. 96-5955. Argued
March 24, 1997-Decided April 28, 1997

															In Wilson v. Arkansas, 514 U. S. 927 , this Court
held that the Fourth Amendment incorporates the common-law
requirement that police knock on a dwelling's door and announce
their identity and purpose before attempting forcible entry,
recognized that the flexible reasonableness requirement should not
be read to mandate a rigid announcement rule that ignores
countervailing law enforcement interests, id., at 934, and
left it to the lower courts to determine the circumstances under
which an unannounced entry is reasonable. Id., at 936.
Officers in Madison, Wisconsin, obtained a warrant to search
petitioner Richards' motel room for drugs and related
paraphernalia, but the Magistrate refused to give advance
authorization for a "no-knock" entry. The officer who knocked on
Richards' door was dressed, and identified himself, as a
maintenance man. Upon opening the door, Richards also saw a
uniformed officer and quickly closed the door. The officers kicked
down the door, caught Richards trying to escape, and found cash and
cocaine in the bathroom. In denying Richards' motion to suppress
the evidence on the ground that the officers did not knock and
announce their presence before forcing entry, the trial court found
that they could gather from Richards' strange behavior that he
might try to destroy evidence or escape and that the drugs'
disposable nature further justified their decision not to knock and
announce. The State Supreme Court affirmed, concluding that Wilson did not preclude the court's pre-Wilson per se rule that police officers are never required to knock and
announce when executing a search warrant in a felony drug
investigation because of the special circumstances of today's drug
culture.

															Held:

															1. The Fourth Amendment does not permit a blanket exception to
the knock-and-announce requirement for felony drug investigations.
While the requirement can give way under circumstances presenting a
threat of physical violence or where officers believe that evidence
would be destroyed if advance notice were given, 514 U. S., at 936,
the fact that felony drug investigations may frequently present
such circumstances cannot remove from the neutral scrutiny of a
reviewing court the reasonableness of the police decision not to
knock and announce in a particular case. Creating exceptions to the
requirement based on the culture surrounding a general category of
criminal behavior presents at 386 Syllabus

															least two serious concerns. First, the exception contains
considerable overgeneralization that would impermissibly insulate
from judicial review cases in which a drug investigation does not
pose special risks. Second, creating an exception in one category
can, relatively easily, be applied to others. If a per se exception were allowed for each criminal activity category that
included a considerable risk of danger to officers or destruction
of evidence, the knock-and-announce requirement would be
meaningless. The court confronted with the question in each case
has a duty to determine whether the facts and circumstances of the
particular entry justified dispensing with the requirement. A
"noknock" entry is justified when the police have a reasonable
suspicion that knocking and announcing their presence, under the
particular circumstances, would be dangerous or futile, or that it
would inhibit the effective investigation of the crime. This
standard strikes the appropriate balance between the legitimate law
enforcement concerns at issue in the execution of search warrants
and the individual privacy interests affected by no-knock entries.
Cf. Maryland v. Buie, 494 U. S. 325 , 337.
Pp.391-395.

															2. Because the evidence in this case establishes that the
decision not to knock and announce was a reasonable one under the
circumstances, the officers' entry into the motel room did not
violate the Fourth Amendment. That the Magistrate had originally
refused to issue a noknock warrant means only that at the time the
warrant was requested there was insufficient evidence for a
no-knock entry. However, the officers' decision to enter the room
must be evaluated as of the time of entry. Pp. 395-396.

															201 Wis. 2d 845, 549 N. W. 2d 218, affirmed.

															STEVENS, J., delivered the opinion for a unanimous Court. David R. Karpe, by appointment of the Court, 519 U. S.
1106, argued the cause for petitioner. With him on the briefs were John Wesley Hall, Jr., Henry R. Schultz, and Jack E.
Schairer. James E. Doyle, Attorney General of Wisconsin, argued the
cause for respondent. With him on the brief was Stephen W
Kleinmaier, Assistant Attorney General.

															Miguel A. Estrada argued the cause for the United States as
amicus curiae urging affirmance. On the brief were Acting Solicitor
General Dellinger, Acting Assistant Attorney 387 General Richard, Deputy Solicitor General Dreeben, James A.
Feldman, and Deborah Watson. * JUSTICE STEVENS delivered the opinion of the Court.

															In Wilson v. Arkansas, 514 U. S. 927 (1995), we
held that the Fourth Amendment incorporates the common-law
requirement that police officers entering a dwelling must knock on
the door and announce their identity and purpose before attempting
forcible entry. At the same time, we recognized that the "flexible
requirement of reasonableness should not be read to mandate a rigid
rule of announcement that ignores countervailing law enforcement
interests," id., at 934, and left "to the lower courts the
task of determining the circumstances under which an unannounced
entry is reasonable under the Fourth Amendment," id., at
936.

															In this case, the Wisconsin Supreme Court concluded that police
officers are never required to knock and announce their
presence when executing a search warrant in a felony *Tracey Maclin, Steven R. Shapiro, and Lisa B.
Kemler filed a brieffor the American Civil Liberties Union et
al. as amici curiae urging reversal.

															Briefs of amici curiae urging affirmance were filed for
the State of Ohio et al. by Betty D. Montgomery, Attorney
General of Ohio, Jeffrey S. Sutton, State Solicitor, Simon B. Karas, and Diane R. Richards, and by the
Attorneys General for their respective jurisdictions as follows: Bill Pryor of Alabama, Bruce M. Botelho of Alaska, Winston Bryant of Arkansas, M. Jane Brady of
Delaware, Robert A. Butterworth of Florida, Gus F. Diaz of Guam, Alan G. Lance of Idaho, James
E. Ryan of Illinois, Carla J. Stovall of
Kansas, A. B. Chandler III of Kentucky, Richard P.
Ieyoub of Louisiana, J. Joseph Curran of
Maryland, Frank J. Kelley of Michigan, Mike
Moore of Mississippi, Joseph P. Mazurek of Montana, Don Stenberg of Nebraska, Thomas J. Miller of Iowa, Frankie Sue Del Papa of Nevada, Steven M. Houran of New Hampshire, Peter Verniero of
New Jersey, Tom Udall of New Mexico, Jose Fuentes
Agostini of Puerto Rico, Jeffrey B. Pine of Rhode
Island, Charles Molony Condon of South Carolina, Mark W
Barnett of South Dakota, Jan Graham of Utah, and James Gilmore III of Virginia; and for Americans for
Effective Law Enforcement, Inc., et al. by Fred E. Inbau, Wayne
W Schmidt, James P. Manak, Richard M. Weintraub, and Bernard J. Farber. 388 drug investigation. In so doing, it reaffirmed a pre-Wilson holding and concluded that Wilson did not
preclude this per se rule. We disagree with the court's
conclusion that the Fourth Amendment permits a blanket exception to
the knock-and-announce requirement for this entire category of
criminal activity. But because the evidence presented to support
the officers' actions in this case establishes that the decision
not to knock and announce was a reasonable one under the
circumstances, we affirm the judgment of the Wisconsin court.

															I

															On December 31, 1991, police officers in Madison, Wisconsin,
obtained a warrant to search Steiney Richards' motel room for drugs
and related paraphernalia. The search warrant was the culmination
of an investigation that had uncovered substantial evidence that
Richards was one of several individuals dealing drugs out of hotel
rooms in Madison. The police requested a warrant that would have
given advance authorization for a "no-knock" entry into the motel
room, but the Magistrate explicitly deleted those portions of the
warrant. App. 7, 9.

															The officers arrived at the motel room at 3:40 a.m. Officer
Pharo, dressed as a maintenance man, led the team. With him were
several plainclothes officers and at least one man in uniform.
Officer Pharo knocked on Richards' door and, responding to the
query from inside the room, stated that he was a maintenance man.
With the chain still on the door, Richards cracked it open.
Although there is some dispute as to what occurred next, Richards
acknowledges that when he opened the door he saw the man in uniform
standing behind Officer Pharo. Brief for Petitioner 6. He quickly
slammed the door closed and, after waiting two or three seconds,
the officers began kicking and ramming the door to gain entry to
the locked room. At trial, the officers testified that they
identified themselves as police while they were kicking the door
in. App. 40. When they finally did break 389 into the room, the officers caught Richards trying to escape
through the window. They also found cash and cocaine hidden in
plastic bags above the bathroom ceiling tiles.

															Richards sought to have the evidence from his motel room
suppressed on the ground that the officers had failed to knock and
announce their presence prior to forcing entry into the room. The
trial court denied the motion, concluding that the officers could
gather from Richards' strange behavior when they first sought entry
that he knew they were police officers and that he might try to
destroy evidence or to escape. Id., at 54. The judge
emphasized that the easily disposable nature of the drugs the
police were searching for further justified their decision to
identify themselves as they crossed the threshold instead of
announcing their presence before seeking entry. Id., at 55.
Richards appealed the decision to the Wisconsin Supreme Court and
that court affirmed. 201 Wis. 2d 845, 549 N. W. 2d 218 (1996).

															The Wisconsin Supreme Court did not delve into the events
underlying Richards' arrest in any detail, but accepted the
following facts: "[O]n December 31, 1991, police executed a search
warrant for the motel room of the defendant seeking evidence of the
felonious crime of Possession with Intent to Deliver a Controlled
Substance in violation of Wis. Stat. § 161.41(lm) (1991-92). They
did not knock and announce prior to their entry. Drugs were
seized." Id., at 849, 549 N. W. 2d, at 220.

															Assuming these facts, the court proceeded to consider whether
our decision in Wilson required the court to abandon its
decision in State v. Stevens, 181 Wis. 2d 410, 511 N.
W. 2d 591 (1994), cert. denied, 515 U. S. 1102 (1995), which held
that "when the police have a search warrant, supported by probable
cause, to search a residence for evidence of delivery of drugs or
evidence of possession with intent to deliver drugs, they
necessarily have reasonable cause to believe exigent circumstances
exist" to justify a no-knock entry. 201 Wis. 2d, at 852, 549 N. W.
2d, at 221. The court concluded 390 that nothing in Wilson's acknowledgment that the
knockand-announce rule was an element of the Fourth Amendment
"reasonableness" requirement would prohibit application of a per
se exception to that rule in a category of cases. 201 Wis. 2d,
at 854-855, 549 N. W. 2d, at 220.

															In reaching this conclusion, the Wisconsin court found it
reasonable-after considering criminal conduct surveys, newspaper
articles, and other judicial opinions-to assume that all felony
drug crimes will involve "an extremely high risk of serious if not
deadly injury to the police as well as the potential for the
disposal of drugs by the occupants prior to entry by the police." Id., at 847-848,549 N. W. 2d, at 219. Notwithstanding its
acknowledgment that in "some cases, police officers will
undoubtedly decide that their safety, the safety of others, and the
effective execution of the warrant dictate that they knock and
announce," id., at 863, 549 N. W. 2d, at 225, the court
concluded that exigent circumstances justifying a no-knock entry
are always present in felony drug cases. Further, the court
reasoned that the violation of privacy that occurs when officers
who have a search warrant forcibly enter a residence without first
announcing their presence is minimal, given that the residents
would ultimately be without authority to refuse the police entry.
The principal intrusion on individual privacy interests in such a
situation, the court concluded, comes from the issuance of the
search warrant, not the manner in which it is executed. Id., at 864-865, 549 N. W. 2d, at 226. Accordingly, the court determined
that police in Wisconsin do not need specific information about
dangerousness, or the possible destruction of drugs in a particular
case, in order to dispense with the knock-and-announce requirement
in felony drug cases.1

															1 Several other state courts-in cases that predate our decision
in Wil son-have adopted similar rules, concluding that simple
probable cause to search a home for narcotics always allows the
police to forgo the knockand-announce requirement. See, e. g.,
People v. Lujan, 484 P. 2d 1238, 1241 (Colo. 1971) (en
bane); Henson v. State, 236 Md. 519, 523-524, 204
A. 391 Justice Abrahamson concurred in the judgment because, in her
view, the facts found by the trial judge justified a no-knock
entry. Id., at 866-868, 549 N. W. 2d, at 227. Specifically,
she noted that Richards' actions in slamming the door when he saw
the uniformed man standing behind Officer Pharo indicated that he
already knew that the people knocking on his door were police
officers. Under these circumstances, any further announcement of
their presence would have been a useless gesture. Id., at
868-869, n. 3, 549 N. W. 2d, at 228, n. 3. While agreeing with the
outcome, Justice Abrahamson took issue with her colleagues'
affirmation of the blanket exception to the knock-and-announce
requirement in drug felony cases. She observed that the
constitutional reasonableness of a search has generally been a
matter left to the court, rather than to the officers who conducted
the search, and she objected to the creation of a blanket rule that
insulated searches in a particular category of crime from the
neutral oversight of a reviewing judge. Id., at 868-875, 549
N. W. 2d, at 228-230.

															II

															We recognized in Wilson that the knock-and-announce
requirement could give way "under circumstances presenting a threat
of physical violence," or "where police officers have reason to
believe that evidence would likely be destroyed if advance notice
were given." 514 U. S., at 936. It is indisputable that felony drug
investigations may frequently involve both of these circumstances.2
The question we must

															2d 516, 519-520 (1964); State v. Loucks, 209 N. W.
2d 772, 777-778 (N. D. 1973). Cf. People v. De Lago, 16 N. Y. 2d 289, 292, 213 N. E. 2d 659, 661 (1965) (similar rule
for searches related to gambling operations), cert. denied, 383 U.
S. 963 (1966).

															2 This Court has encountered before the links between drugs and
violence, see, e. g., Michigan v. Summers, 452 U. S. 692 , 702
(1981), and the likelihood that drug dealers will attempt to
dispose of drugs before police seize them, see, e. g., Ker v. California, 374 U. S. 23 , 28, n. 3
(1963). 392 resolve is whether this fact justifies dispensing with
caseby-case evaluation of the manner in which a search was
executed.3

															The Wisconsin court explained its blanket exception as
necessitated by the special circumstances of today's drug culture,
201 Wis. 2d, at 863-866, 549 N. W. 2d, at 226-227, and the State
asserted at oral argument that the blanket exception was reasonable
in "felony drug cases because of the convergence in a violent and
dangerous form of commerce of weapons and the destruction of
drugs." Tr. of Oral Arg. 26. But creating exceptions to the
knock-and-announce rule based on the "culture" surrounding a
general category of criminal behavior presents at least two serious
concerns.4

															3 Although our decision in Wilson did not address this
issue directly, it is instructive that in that case-which involved
a felony drug investigation-we remanded to the state court for
further factual development to determine whether the no-knock entry
was reasonable under the circumstances of the case. Two amicus briefs in Wilson suggested that we adopt just
the sort of per se rule the Wisconsin court propounded here.
Brief for Americans for Effective Law Enforcement, Inc., et al. as Amici Curiae 10-11, Brief for Wayne County, Michigan, as Amicus Curiae 39 46, in Wilson v. Arkansas, O.
T. 1994, No. 5707. Although the respondent did not argue for a
categorical rule, the petitioner, in her reply brief, did address
the arguments put forward by the amicus briefs, Reply Brief
for Petitioner in Wilson v. Arkansas, O. T. 1994, No.
5707, p. 11, and amici supporting the petitioner also
presented arguments against a categorical rule. Brief for American
Civil Liberties Union et al. as Amici Curiae in Wilson v. Arkansas, O. T. 1994, No. 5707, p. 29, n.
44. Thus, while the prospect of a categorical rule was one to which
we were alerted in Wilson, we did not choose to adopt such a
rule at that time.

															4 It is always somewhat dangerous to ground exceptions to
constitutional protections in the social norms of a given
historical moment. The purpose of the Fourth Amendment's
requirement of reasonableness "is to preserve that degree of
respect for the privacy of persons and the inviolability of their
property that existed when the provision was adopted-even if a
later, less virtuous age should become accustomed to considering
all sorts of intrusion 'reasonable.''' Minnesota v. Dickerson, 508
U. S. 366 , 380 (1993) (SCALIA, J., concurring). 393 First, the exception contains considerable overgeneralization.
For example, while drug investigation frequently does pose special
risks to officer safety and the preservation of evidence, not every
drug investigation will pose these risks to a substantial degree.
For example, a search could be conducted at a time when the only
individuals present in a residence have no connection with the drug
activity and thus will be unlikely to threaten officers or destroy
evidence. Or the police could know that the drugs being searched
for were of a type or in a location that made them impossible to
destroy quickly. In those situations, the asserted governmental
interests in preserving evidence and maintaining safety may not
outweigh the individual privacy interests intruded upon by a
no-knock entry. 5 Wisconsin's blanket rule impermissibly insulates
these cases from judicial review.

															A second difficulty with permitting a criminal-category
exception to the knock-and-announce requirement is that the

															5 The State asserts that the intrusion on individual interests
effectuated by a no-knock entry is minimal because the execution of
the warrant itself constitutes the primary intrusion on individual
privacy and that the individual privacy interest cannot outweigh
the generalized governmental interest in effective and safe law
enforcement. Brieffor Respondent 21-24. See also Brieffor United
States as Amicus Curiae 16 ("occupants' privacy interest is
necessarily limited to the brief interval between the officers'
announcement and their entry"). While it is true that a no-knock
entry is less intrusive than, for example, a warrantless search,
the individual interests implicated by an unannounced, forcible
entry should not be unduly minimized. As we observed in Wilson v. Arkansas, 514 U. S. 927 , 930-932
(1995), the common law recognized that individuals should be
provided the opportunity to comply with the law and to avoid the
destruction of property occasioned by a forcible entry. These
interests are not inconsequential.

															Additionally, when police enter a residence without announcing
their presence, the residents are not given any opportunity to
prepare themselves for such an entry. The State pointed out at oral
argument that, in Wisconsin, most search warrants are executed
during the late night and early morning hours. Tr. of Oral Arg. 24.
The brief interlude between announcement and entry with a warrant
may be the opportunity that an individual has to pull on clothes or
get out of bed. 394 reasons for creating an exception in one category can,
relatively easily, be applied to others. Armed bank robbers, for
example, are, by definition, likely to have weapons, and the fruits
of their crime may be destroyed without too much difficulty. If a per se exception were allowed for each category of criminal
investigation that included a considerable-albeit hypothetical-risk
of danger to officers or destruction of evidence, the
knock-and-announce element of the Fourth Amendment's reasonableness
requirement would be meaningless.

															Thus, the fact that felony drug investigations may frequently
present circumstances warranting a no-knock entry cannot remove
from the neutral scrutiny of a reviewing court the reasonableness
of the police decision not to knock and announce in a particular
case. Instead, in each case, it is the duty of a court confronted
with the question to determine whether the facts and circumstances
of the particular entry justified dispensing with the
knock-and-announce requirement.

															In order to justify a "no-knock" entry, the police must have a
reasonable suspicion that knocking and announcing their presence,
under the particular circumstances, would be dangerous or futile,
or that it would inhibit the effective investigation of the crime
by, for example, allowing the destruction of evidence. This
standard-as opposed to a probable-cause requirement-strikes the
appropriate balance between the legitimate law enforcement concerns
at issue in the execution of search warrants and the individual
privacy interests affected by no-knock entries. Cf. Maryland v. Buie, 494
U. S. 325 , 337 (1990) (allowing a protective sweep of a house
during an arrest where the officers have "a reasonable belief based
on specific and articulable facts that the area to be swept harbors
an individual posing a danger to those on the arrest scene"); Terry v. Ohio, 392 U. S. 1 , 30 (1968)
(requiring a reasonable and articulable suspicion of danger to
justify a patdown search). This showing is not high, but the
police 395 should be required to make it whenever the reasonableness of a
no-knock entry is challenged.

															III

															Although we reject the Wisconsin court's blanket exception to
the knock-and-announce requirement, we conclude that the officers'
no-knock entry into Richards' motel room did not violate the Fourth
Amendment. We agree with the trial court, and with Justice
Abrahamson, that the circumstances in this case show that the
officers had a reasonable suspicion that Richards might destroy
evidence if given further opportunity to do SO.6

															The judge who heard testimony at Richards' suppression hearing
concluded that it was reasonable for the officers executing the
warrant to believe that Richards knew, after opening the door to
his motel room the first time, that the men seeking entry to his
room were the police. App. 54. Once the officers reasonably
believed that Richards knew who they were, the court concluded, it
was reasonable for them to force entry immediately given the
disposable nature of the drugs. Id., at 55.

															In arguing that the officers' entry was unreasonable, Richards
places great emphasis on the fact that the Magistrate who signed
the search warrant for his motel room deleted the portions of the
proposed warrant that would have given the officers permission to
execute a no-knock entry. But this fact does not alter the
reasonableness of the officers' decision, which must be evaluated
as of the time they entered the motel room. At the time the
officers obtained the warrant, they did not have evidence
sufficient, in the judgment of the Magistrate, to justify a
no-knock warrant. Of course,

															6We note that the attorneys general of 26 States, the
Commonwealth of Puerto Rico, and the Territory of Guam filed an amicus brief taking the position that the officers' decision
was reasonable under the specific facts of this case, but rejecting
Wisconsin's per se rule. See Brief for Ohio et al. as Amici Curiae. 396 the Magistrate could not have anticipated in every particular
the circumstances that would confront the officers when they
arrived at Richards' motel room.7 These actual
circumstances-petitioner's apparent recognition of the officers
combined with the easily disposable nature of the drugsjustified
the officers' ultimate decision to enter without first announcing
their presence and authority.

															Accordingly, although we reject the blanket exception to the
knock-and-announce requirement for felony drug investigations, the
judgment of the Wisconsin Supreme Court is affirmed.

															It is so ordered.

															7 A number of States give magistrate judges the authority to
issue "noknock" warrants if the officers demonstrate ahead of time
a reasonable suspicion that entry without prior announcement will
be appropriate in a particular context. See, e. g., 725 Ill. Compo Stat., ch. 725, § 5/108-8 (1992); Neb. Rev. Stat.
§29-411 (1995); Okla. Stat., Tit. 22, § 1228 (Supp. 1997); S. D.
Codified Laws § 23A-35-9 (1988); Utah Code Ann. § 77-23-210 (1995).
But see State V. Arce, 83 Ore. App. 185, 730 P. 2d
1260 (1986) (magistrate has no authority to abrogate
knock-and-announce requirement); State V. Bamber, 630
So. 2d 1048 (Fla. 1994) (same).

															The practice of allowing magistrates to issue no-knock warrants
seems entirely reasonable when sufficient cause to do so can be
demonstrated ahead of time. But, as the facts of this case
demonstrate, a magistrate's decision not to authorize a no-knock
entry should not be interpreted to remove the officers' authority
to exercise independent judgment concerning the wisdom of a
no-knock entry at the time the warrant is being executed.


OCTOBER TERM, 1999

															Syllabus

															FLORIDA v. J. L.

															CERTIORARI TO THE SUPREME COURT OF FLORIDA No. 98-1993. Argued
February 29, 2000-Decided March 28, 2000

															After an anonymous caller reported to the Miami-Dade Police that
a young black male standing at a particular bus stop and wearing a
plaid shirt was carrying a gun, officers went to the bus stop and
saw three black males, one of whom, respondent J. L., was wearing a
plaid shirt. Apart from the tip, the officers had no reason to
suspect any of the three of illegal conduct. The officers did not
see a firearm or observe any unusual movements. One of the officers
frisked J. L. and seized a gun from his pocket. J. L., who was then
almost 16, was charged under state law with carrying a concealed
firearm without a license and possessing a firearm while under the
age of 18. The trial court granted his motion to suppress the gun
as the fruit of an unlawful search. The intermediate appellate
court reversed, but the Supreme Court of Florida quashed that
decision and held the search invalid under the Fourth
Amendment. Held: An anonymous tip that a person is carrying a gun is
not, without more, sufficient to justify a police officer's stop
and frisk of that person. An officer, for the protection of himself
and others, may conduct a carefully limited search for weapons in
the outer clothing of persons engaged in unusual conduct where, inter alia, the officer reasonably concludes in light of his
experience that criminal activity may be afoot and that the persons
in question may be armed and presently dangerous. Terry v. Ohio, 392 U. S.
1 , 30. Here, the officers' suspicion that J. L. was carrying a
weapon arose not from their own observations but solely from a call
made from an unknown location by an unknown caller. The tip lacked
sufficient indicia of reliability to provide reasonable suspicion
to make a Terry stop: It provided no predictive information
and therefore left the police without means to test the informant's
knowledge or credibility. See Alabama v. White, 496 U. S. 325 ,
327. The contentions of Florida and the United States as amicus that the tip was reliable because it accurately
described J. L.'s visible attributes misapprehend the reliability
needed for a tip to justify a Terry stop. The reasonable
suspicion here at issue requires that a tip be reliable in its
assertion of illegality, not just in its tendency to identify a
determinate person. This Court also declines to adopt the argument
that the standard Terry analysis should be modified to
license a "firearm exception," under which a tip alleging an
illegal gun would justify a stop and frisk even if 267 the accusation would fail standard pre-search reliability
testing. The facts of this case do not require the Court to
speculate about the circumstances under which the danger alleged in
an anonymous tip might be so great--e. g., a report of a
person carrying a bomb-as to justify a search even without a
showing of reliability. Pp.269-274.

															727 So. 2d 204, affirmed.

															GINSBURG, J., delivered the opinion for a unanimous Court.
KENNEDY, J., filed a concurring opinion, in which REHNQUIST, C. J.,
joined, post, p.274. Michael J. Neimand, Assistant Attorney
General of Florida, argued the cause for petitioner. With him on
the briefs was Robert A. Butterworth, Attorney General.

															Irving L. Gornstein argued the cause for the United States as
amicus curiae urging reversal. With him on the brief were Solicitor
General Waxman, Assistant Attorney General Robinson, and Deputy
Solicitor General Dreeben. Harvey J. Sepler argued the cause for respondent. With
him on the brief were Bennett H. Brummer and Andrew
Stanton. *

															*Briefs of amici curiae urging reversal were filed for
Americans for Effective Law Enforcement, Inc., et al. by Wayne W
Schmidt, James P. Manak, Richard Weintraub, and Bernard J. Farber; for the Justice Coalition by Scott D.
Makar; for the National Association of Police Organizations by Stephen R. McSpadden; and for the State of Illinois et al.
by James E. Ryan, Attorney General of Illinois, Joel D.
Bertocchi, Solicitor General, William Browers and Michael M. Glick, Assistant Attorneys General, and Dan
Schweitzer, joined by the Attorneys General for their
respective jurisdictions as follows: Bill Pryor of Alabama, Janet Napolitano of Arizona, Mark Pryor of Arkansas, Bill Lockyer of California, Ken Salazar of Colorado, John M. Bailey of Connecticut, M. Jane Brady of
Delaware, Earl I. Anzai of Hawaii, Jeffrey A.
Modisett of Indiana, Thomas J. Miller of
Iowa, Carla J. Stovall of Kansas, Richard
P. Ieyoub of Louisiana, J. Joseph Curran of
Maryland, Jennifer M. Granholm of Michigan, Mike
Hatch of Minnesota, Jeremiah W (Jay) Nixon of Missouri, Joseph P. Mazurek of Montana, Frankie Sue Del Papa of
Nevada, Philip T. McLaughlin of New Hampshire, Patricia
A. Madrid of New Mexico, Michael F. Easley of
North Carolina, Betty D. Montgomery of Ohio, W A. Drew
Edmondson of Oklahoma, Hardy Myers of Oregon, D.
Michael Fisher of 268 JUSTICE GINSBURG delivered the opinion of the Court. The
question presented in this case is whether an anonymous tip that a
person is carrying a gun is, without more, sufficient to justify a
police officer's stop and frisk of that person. We hold that it is
not.

															I

															On October 13, 1995, an anonymous caller reported to the
Miami-Dade Police that a young black male standing at a particular
bus stop and wearing a plaid shirt was carrying a gun. App. to Pet.
for Cert. A-40 to A-41. So far as the record reveals, there is no
audio recording of the tip, and nothing is known about the
informant. Sometime after the police received the tip-the record
does not say how longtwo officers were instructed to respond. They
arrived at the bus stop about six minutes later and saw three black
males "just hanging out [there]." Id., at A-42. One of the
three, respondent J. L., was wearing a plaid shirt. Id., at
A-41. Apart from the tip, the officers had no reason to suspect any
of the three of illegal conduct. The officers did not see a
firearm, and J. L. made no threatening or otherwise unusual
movements. Id., at A-42 to A-44. One of the officers
approached J. L., told him to put his hands up on the bus stop,
frisked him, and seized a gun from J. L.'s pocket. The second
officer frisked the other two individuals, against whom no
allegations had been made, and found nothing.

															Pennsylvania, Jose A. Fuentes Agostini of Puerto Rico, Sheldon Whitehouse of Rhode Island, Charles M. Condon of South Carolina, Paul G. Summers of Tennessee, John Cornyn of Texas, Jan Graham of Utah, Christine O. Gregoire of Washington, and Gay
Woodhouse of Wyoming.

															Briefs of amici curiae urging affirmance were filed for
the Congress of Racial Equality, Inc., by Stefan B.
Tahmassebi; for the National Association of Criminal Defense
Lawyers et al. by James J. Tomkovicz and Barbara E. Bergman; for the National Rifle Association of
America et al. by Robert Dowlut and David B. Kopel; and for the Rutherford Institute by John W Whitehead and Steven H. Aden. 269 J. L., who was at the time of the frisk "10 days shy of his 16th
birth[day]," Tr. of Oral Arg. 6, was charged under state law with
carrying a concealed firearm without a license and possessing a
firearm while under the age of 18. He moved to suppress the gun as
the fruit of an unlawful search, and the trial court granted his
motion. The intermediate appellate court reversed, but the Supreme
Court of Florida quashed that decision and held the search invalid
under the Fourth Amendment. 727 So. 2d 204 (1998).

															Anonymous tips, the Florida Supreme Court stated, are generally
less reliable than tips from known informants and can form the
basis for reasonable suspicion only if accompanied by specific
indicia of reliability, for example, the correct forecast of a
subject's "'not easily predicted'" movements. Id., at 207
(quoting Alabama v. White, 496 U. S. 325 , 332
(1990)). The tip leading to the frisk of J. L., the court observed,
provided no such predictions, nor did it contain any other
qualifying indicia of reliability. 727 So. 2d, at 207-208. Two
justices dissented. The safety of the police and the public, they
maintained, justifies a "firearm exception" to the general rule
barring investigatory stops and frisks on the basis of bare-boned
anonymous tips. Id., at 214-215.

															Seeking review in this Court, the State of Florida noted that
the decision of the State's Supreme Court conflicts with decisions
of other courts declaring similar searches compatible with the
Fourth Amendment. See, e. g., United States v. DeBerry, 76 F.3d
884 , 886-887 (CA7 1996); United States v. Clipper, 973 F.2d
944 , 951 (CADC 1992). We granted certiorari, 528 U. S.
963 (1999), and now affirm the judgment of the Florida Supreme
Court.

															II

															Our "stop and frisk" decisions begin with Terry v. Ohio, 392 U. S.
1 (1968). This Court held in Terry: "[W]here a police officer observes unusual conduct which leads
him reasonably to conclude in light of his 270 experience that criminal activity may be afoot and that the
persons with whom he is dealing may be armed and presently
dangerous, where in the course of investigating this behavior he
identifies himself as a policeman and makes reasonable inquiries,
and where nothing in the initial stages of the encounter serves to
dispel his reasonable fear for his own or others' safety, he is
entitled for the protection of himself and others in the area to
conduct a carefully limited search of the outer clothing of such
persons in an attempt to discover weapons which might be used to
assault him." Id., at 30. In the instant case, the officers' suspicion that J. L. was
carrying a weapon arose not from any observations of their own but
solely from a call made from an unknown location by an unknown
caller. Unlike a tip from a known informant whose reputation can be
assessed and who can be held responsible if her allegations turn
out to be fabricated, see Adams v. Williams, 407 U. S. 143 , 146-147
(1972), "an anonymous tip alone seldom demonstrates the informant's
basis of knowledge or veracity," Alabama v. White, 496 U. S., at 329. As we have recognized, however, there are
situations in which an anonymous tip, suitably corroborated,
exhibits "sufficient indicia of reliability to provide reasonable
suspicion to make the investigatory stop." Id., at 327. The
question we here confront is whether the tip pointing to J. L. had
those indicia of reliability.

															In White, the police received an anonymous tip asserting
that a woman was carrying cocaine and predicting that she would
leave an apartment building at a specified time, get into a car
matching a particular description, and drive to a named motel. Ibid. Standing alone, the tip would not have justified a Terry stop. 496 U. S., at 329. Only after police observation
showed that the informant had accurately predicted the woman's
movements, we explained, did it become reasonable to think the
tipster had inside knowledge about the suspect and therefore to
credit his assertion about the cocaine. 271 Id., at 332. Although the Court held that the suspicion
in White became reasonable after police surveillance, we
regarded the case as borderline. Knowledge about a person's future
movements indicates some familiarity with that person's affairs,
but having such knowledge does not necessarily imply that the
informant knows, in particular, whether that person is carrying
hidden contraband. We accordingly classified White as a
"close case." Ibid. The tip in the instant case lacked the moderate indicia of
reliability present in White and essential to the Court's
decision in that case. The anonymous call concerning J. L. provided
no predictive information and therefore left the police without
means to test the informant's knowledge or credibility. That the
allegation about the gun turned out to be correct does not suggest
that the officers, prior to the frisks, had a reasonable basis for
suspecting J. L. of engaging in unlawful conduct: The
reasonableness of official suspicion must be measured by what the
officers knew before they conducted their search. All the police
had to go on in this case was the bare report of an unknown,
unaccountable informant who neither explained how he knew about the
gun nor supplied any basis for believing he had inside information
about J. L. If White was a close case on the reliability of
anonymous tips, this one surely falls on the other side of the
line.

															Florida contends that the tip was reliable because its
description of the suspect's visible attributes proved
accurate:

															There really was a young black male wearing a plaid shirt at the
bus stop. Brief for Petitioner 20-21. The United States as amicus curiae makes a similar argument, proposing that a
stop and frisk should be permitted "when (1) an anonymous tip
provides a description of a particular person at a particular
location illegally carrying a concealed firearm, (2) police
promptly verify the pertinent details of the tip except the
existence of the firearm, and (3) there are no factors that cast
doubt on the reliability of the tip .... " Brief 272 for United States 16. These contentions misapprehend the
reliability needed for a tip to justify a Terry stop.

															An accurate description of a subject's readily observable
location and appearance is of course reliable in this limited
sense: It will help the police correctly identify the person whom
the tipster means to accuse. Such a tip, however, does not show
that the tipster has knowledge of concealed criminal activity. The
reasonable suspicion here at issue requires that a tip be reliable
in its assertion of illegality, not just in its tendency to
identify a determinate person. Cf. 4 W. LaFave, Search and Seizure
§ 9.4(h), p. 213 (3d ed. 1996) (distinguishing reliability as to
identification, which is often important in other criminal law
contexts, from reliability as to the likelihood of criminal
activity, which is central in anonymous-tip cases).

															A second major argument advanced by Florida and the United
States as amicus is, in essence, that the standard Terry analysis should be modified to license a "firearm
exception." Under such an exception, a tip alleging an illegal gun
would justify a stop and frisk even if the accusation would fail
standard pre-search reliability testing. We decline to adopt this
position.

															Firearms are dangerous, and extraordinary dangers sometimes
justify unusual precautions. Our decisions recognize the serious
threat that armed criminals pose to public safety; Terry's rule, which permits protective police searches on the basis of
reasonable suspicion rather than demanding that officers meet the
higher standard of probable cause, responds to this very concern.
See 392 U. S., at 30. But an automatic firearm exception to our
established reliability analysis would rove too far. Such an
exception would enable any person seeking to harass another to set
in motion an intrusive, embarrassing police search of the targeted
person simply by placing an anonymous call falsely reporting the
target's unlawful carriage of a gun. Nor could one securely confine
such an exception to allegations involving firearms. 273 Several Courts of Appeals have held it per se foreseeable
for people carrying significant amounts of illegal drugs to be
carrying guns as well. See, e. g., United States v. Sakyi, 160 F. 3d 164, 169 (CA4 1998); United
States v. Dean, 59 F.3d
1479 , 1490, n. 20 (CA5 1995); United States v. Odom, 13 F.3d
949 , 959 (CA6 1994); United States v. Martinez, 958 F.2d
217 , 219 (CA8 1992). If police officers may properly
conduct Terry frisks on the basis of bare-boned tips about
guns, it would be reasonable to maintain under the above-cited
decisions that the police should similarly have discretion to frisk
based on bare-boned tips about narcotics. As we clarified when we
made indicia of reliability critical in Adams and White, the Fourth Amendment is not so easily satisfied. Cf. Richards v. Wisconsin, 520 U. S. 385 , 393-394
(1997) (rejecting a per se exception to the "knock and
announce" rule for narcotics cases partly because "the reasons for
creating an exception in one category [of Fourth Amendment cases]
can, relatively easily, be applied to others," thus allowing the
exception to swallow the rule). *

															The facts of this case do not require us to speculate about the
circumstances under which the danger alleged in an anonymous tip
might be so great as to justify a search even without a showing of
reliability. We do not say, for example, that a report of a person
carrying a bomb need bear the

															* At oral argument, petitioner also advanced the position that
J. L.'s youth made the stop and frisk valid, because it is a crime
in Florida for persons under the age of 21 to carry concealed
firearms. See Fla. Stat. § 790.01 (1997) (carrying a concealed
weapon without a license is a misdemeanor), § 790.06(2)(b) (only
persons aged 21 or older may be licensed to carry concealed
weapons). This contention misses the mark. Even assuming that the
arresting officers could be sure that J. L. was under 21, they
would have had reasonable suspicion that J. L. was engaged in
criminal activity only if they could be confident that he was
carrying a gun in the first place. The mere fact that a tip, if
true, would describe illegal activity does not mean that the police
may make a Terry stop without meeting the reliability
requirement, and the fact that J. L. was under 21 in no way made
the gun tip more reliable than if he had been an adult. 274 indicia of reliability we demand for a report of a person
carrying a firearm before the police can constitutionally conduct a
frisk. Nor do we hold that public safety officials in quarters
where the reasonable expectation of Fourth Amendment privacy is
diminished, such as airports, see Florida v. Rodriguez, 469
U. S. 1 (1984) (per curiam), and schools, see New
Jersey v. T. L. 0., 469 U. S. 325 (1985),
cannot conduct protective searches on the basis of information
insufficient to justify searches elsewhere.

															Finally, the requirement that an anonymous tip bear standard
indicia of reliability in order to justify a stop in no way
diminishes a police officer's prerogative, in accord with Terry, to conduct a protective search of a person who has
already been legitimately stopped. We speak in to day's decision
only of cases in which the officer's authority to make the initial
stop is at issue. In that context, we hold that an anonymous tip
lacking indicia of reliability of the kind contemplated in Adams and White does not justify a stop and frisk
whenever and however it alleges the illegal possession of a
firearm.

															The judgment of the Florida Supreme Court is affirmed.

															It is so ordered.

															JUSTICE KENNEDY, with whom THE CHIEF JUSTICE joins,
concurring.

															On the record created at the suppression hearing, the Court's
decision is correct. The Court says all that is necessary to
resolve this case, and I join the opinion in all respects. It might
be noted, however, that there are many indicia of reliability
respecting anonymous tips that we have yet to explore in our
cases.

															When a police officer testifies that a suspect aroused the
officer's suspicion, and so justifies a stop and frisk, the courts
can weigh the officer's credibility and admit evidence seized
pursuant to the frisk even if no one, aside from the officer and
defendant themselves, was present or observed the sei- 275 zure. An anonymous telephone tip without more is different,
however; for even if the officer's testimony about receipt of the
tip is found credible, there is a second layer of inquiry
respecting the reliability of the informant that cannot be pursued.
If the telephone call is truly anonymous, the informant has not
placed his credibility at risk and can lie with impunity. The
reviewing court cannot judge the credibility of the informant and
the risk of fabrication becomes unacceptable.

															On this record, then, the Court is correct in holding that the
telephone tip did not justify the arresting officer's immediate
stop and frisk of respondent. There was testimony that an anonymous
tip came in by a telephone call and nothing more. The record does
not show whether some notation or other documentation of the call
was made either by a voice recording or tracing the call to a
telephone number. The prosecution recounted just the tip itself and
the later verification of the presence of the three young men in
the circumstances the Court describes.

															It seems appropriate to observe that a tip might be anonymous in
some sense yet have certain other features, either supporting
reliability or narrowing the likely class of informants, so that
the tip does provide the lawful basis for some police action. One
such feature, as the Court recognizes, is that the tip predicts
future conduct of the alleged criminal. There may be others. For
example, if an unnamed caller with a voice which sounds the same
each time tells police on two successive nights about criminal
activity which in fact occurs each night, a similar call on the
third night ought not be treated automatically like the tip in the
case now before us. In the instance supposed, there would be a
plausible argument that experience cures some of the uncertainty
surrounding the anonymity, justifying a proportionate police
response. In to day's case, however, the State provides us with no
data about the reliability of anonymous tips. Nor do we know
whether the dispatcher or arresting officer had any 276 objective reason to believe that this tip had some particular
indicia of reliability.

															If an informant places his anonymity at risk, a court can
consider this factor in weighing the reliability of the tip. An
instance where a tip might be considered anonymous but nevertheless
sufficiently reliable to justify a proportionate police response
may be when an unnamed person driving a car the police officer
later describes stops for a moment and, face to face, informs the
police that criminal activity is occurring. This too seems to be
different from the tip in the present case. See United
States v. Sierra-Hernandez, 581 F.2d 760 (CA9
1978). Instant caller identification is widely available to police,
and, if anonymous tips are proving unreliable and distracting to
police, squad cars can be sent within seconds to the location of
the telephone used by the informant. Voice recording of telephone
tips might, in appropriate cases, be used by police to locate the
caller. It is unlawful to make false reports to the police, e. g., Fla. Stat. Ann. § 365.171(16) (Supp. 2000);
Fla. Stat. § 817.49 (1994), and the ability of the police to trace
the identity of anonymous telephone informants may be a factor
which lends reliability to what, years earlier, might have been
considered unreliable anonymous tips.

															These matters, of course, must await discussion in other cases,
where the issues are presented by the record.