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.
Plea bargaining in the United States
Several features of the American justice system tend to promote plea bargaining. The adversarial nature of the system puts judges in a passive role, in which they are completely dependent upon the parties to develop the factual record and cannot independently discover information with which to assess the strength of the case against the defendant. The parties thus can control the outcome of the case by exercising their rights or bargaining them away. The lack of compulsory prosecution also gives prosecutors greater discretion. And the inability of crime victims to mount a private prosecution and their limited ability to influence plea agreements also tends to encourage plea bargaining. Prosecutors have been described as monopsonists.