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
In the U.S. federal system, the court must also satisfy itself that there is a factual basis for the guilty plea. However, this safeguard may not be very effective, because the parties, having reached a plea agreement, may be reluctant to reveal any information that could disturb the agreement. When a plea agreement has been made, the judge's factual basis inquiry is usually perfunctory, and the standard for finding that the plea is factually based is very low.