Plea bargaining in the United States
The constitutionality of plea bargaining was established by "Brady v. United States" in 1970, although the Supreme Court warned that plea incentives which were sufficiently large or coercive as to over-rule defendants' abilities to act freely, or used in a manner giving rise to a significant number of innocent people pleading guilty, might be prohibited or lead to concerns over constitutionality. "Santobello v. New York" added that when plea bargains are broken, legal remedies exist.
United States constitutional criminal procedure
The government is not required to disclose impeachment material prior to plea bargaining. Whether the government must disclose exculpatory material during plea bargaining is an open question."It has long been accepted that a person whose mental condition is such that he lacks the capacity to understand the nature and object of the proceedings against him, to consult with counsel, and to assist in preparing his defense may not be subjected to a trial" consistent with the Due Process Clause. The "test" is "whether he has sufficient present ability to consult with his lawyer with a reasonable degree of rational understanding—and whether he has a rational as well as factual understanding of the proceedings against him."