In Shea v. Louisiana, the U.S. Supreme Court ruled that its decision in Edwards v. Arizona (1981) should be applied retroactively to cases still pending on direct appeal when Edwards was decided. In the original case of Edwards v. Arizona, it was established that once a defendant has invoked his right to counsel during custodial interrogation by police, any waiver of that right must be initiated by the defendant himself and not by law enforcement officers or prosecutors. The petitioner in Shea v. Louisiana had been convicted for armed robbery before this ruling came into effect but appealed after it did so; he argued that his confession had been obtained in violation of these new standards set out in Edwards because he hadn't initiated further discussions with police after asking for an attorney. The court agreed with him and held 7-2 that since his case was still under review when they made their decision about how rights to counsel work during interrogations, those rules should apply to him as well - even though they weren't yet established at the time of his trial.

In the dissenting opinion for Shea v. Louisiana, Justice William Rehnquist disagreed with the majority's decision to retroactively apply Edwards v. Arizona, a case that established an accused person's right to have counsel present during custodial interrogation after invoking their Fifth Amendment rights. He argued that this ruling should not be applied retroactively because it was a new procedural rule rather than a substantive change in criminal law or procedure. According to him, applying such rules retrospectively could potentially disrupt finality in legal proceedings and undermine public confidence in the judicial system by suggesting that court decisions are subject to constant revision. Furthermore, he contended that there were no special considerations of fairness or reliability which would justify retrospective application of Edwards' rule in this particular case.