In Thompson v. United States (1970), the Supreme Court ruled on a case involving the interpretation of Rule 11 of Federal Rules of Criminal Procedure, which relates to pleas in federal courts. The petitioner, Thompson, had pleaded guilty to an indictment for bank robbery but later sought to withdraw his plea before sentencing. He claimed that he was not informed by the court about the nature of the charge against him and did not understand it when entering his plea. The District Court denied his motion and sentenced him based on his guilty plea. The Supreme Court held that under Rule 11, it is mandatory for a judge accepting a defendant's guilty plea to personally address them in open court about their understanding of what they are charged with and ensure they comprehend possible penalties associated with their charges before accepting their pleas. In this case, since there was no record showing such dialogue between Thompson and the trial judge at any point during proceedings prior to or contemporaneous with entry of his guilty plea; hence it violated Rule 11 requirements making acceptance invalid.

In the dissenting opinion for Thompson v. United States, Justice Harlan argued that the majority's decision to reverse and remand was based on an incorrect interpretation of Rule 11 of Federal Rules of Criminal Procedure. He believed that there was no violation in this case as he interpreted Rule 11 as only requiring a judge to ensure a defendant understands the nature of charges against them and does not require judges to explain possible defenses or consequences outside those directly related to sentencing. In his view, Thompson had been adequately informed about his rights before pleading guilty; therefore, there should be no reason for reversal or remand. Furthermore, he expressed concern over how such broad interpretations could lead courts into areas better left for legislative bodies while also creating uncertainty around plea bargaining processes which are crucial in criminal justice system efficiency.