In the case of Mabry, Commissioner, Arkansas Department of Correction v. Johnson in 1983, the U.S. Supreme Court ruled that a plea agreement is not binding until it has been accepted by the court. The defendant, Johnson had initially agreed to plead guilty to a lesser charge in exchange for a reduced sentence but later withdrew his plea after learning that he would be eligible for parole sooner than expected under his original sentence. When prosecutors subsequently offered him another deal with less favorable terms and then refused to honor their initial offer when he tried to accept it again, Johnson argued that they were obligated to stick with their first proposal because he had relied on it when deciding how to plead. However, the Supreme Court disagreed and held that since neither offer had ever been approved by a judge as required by law before becoming final and enforceable; therefore there was no breach of contract or violation of due process rights.

In the dissenting opinion for Mabry v. Johnson, Justice Brennan disagreed with the majority's decision that a plea agreement is not binding until it has been formally accepted by the court. He argued that this interpretation undermines the integrity of plea negotiations and can lead to unfair treatment of defendants. According to Brennan, once a prosecutor makes an offer and a defendant accepts it, both parties should be bound by their agreement regardless of whether or not it has been officially approved by a judge. This would ensure fairness in all stages of criminal proceedings and prevent prosecutors from withdrawing offers arbitrarily after they have already been agreed upon.