Plea bargaining is criticized, particularly outside the United States, on the grounds that its close relationship with rewards, threats and coercion potentially endangers the correct legal outcome.Coercive plea bargaining has been criticized on the grounds that it infringes an individual's rights under Article 8 of the European Convention on Human Rights, incorporated in the UK's Human Rights Act 1998.
In the 1991 book Presumed Guilty: When Innocent People Are Wrongly Convicted, author Martin Yant discusses the use of coercion in plea bargaining. (p. 172)
Even when the charges are more serious, prosecutors often can still bluff defense attorneys and their clients into pleading guilty to a lesser offense. As a result, people who might have been acquitted because of lack of evidence, but also who are in fact truly innocent, will often plead guilty to the charge. Why? In a word, fear. And the more numerous and serious the charges, studies have shown, the greater the fear. That explains why prosecutors sometimes seem to file every charge imaginable against defendants.
Agency problems sometimes arise in plea bargaining in that although the prosecutor represents the people and the defense attorney represents the defendant, these agents' goals may be far from congruent with those of their principals. Moreover, prosecutors and defense attorneys often view each other as colleagues and generally wish to maintain good relations with one another. A defense attorney often receives a flat fee or in any event will not receive enough "additional money" if he goes to trial to cover the costs of doing so; this can create an incentive to plea bargain, even at the expense of the defense attorney's (client's interests!)
Plea bargaining has been defended as a voluntary exchange that leaves both parties better off, in that defendants have many procedural and substantive rights, but by pleading guilty, defendants sell these rights to the prosecutor, receiving concessions that they esteem more highly than the rights surrendered. It has been argued that plea bargaining benefits society by ensuring that the guilty are not acquitted.
Plea bargaining is a significant part of the criminal justice system in the United States; the vast majority (roughly 90%)of criminal cases in the United States are settled by plea bargain rather than by a jury trial
