In the case of Fontaine v. United States in 1972, the Supreme Court ruled that a confession made while under medical treatment could not be used as evidence. The defendant, Mr. Fontaine, was seriously injured and hospitalized after attempting to escape from federal custody. While receiving treatment for his injuries and under heavy sedation, he confessed to several crimes without being informed of his rights or having an attorney present. The court held that due to his physical condition at the time of questioning and lack of legal counsel or knowledge about self-incrimination rights, Mr.Fontaine's statements were involuntary thus violating Fifth Amendment protections against self-incrimination.

In the dissenting opinion for Fontaine v. United States, Justice William Rehnquist argued that the majority's decision to reverse and remand was based on an incorrect interpretation of a previous case (Townsend v. Sain). He contended that Townsend did not establish a rule requiring federal courts to hold evidentiary hearings in all habeas corpus cases where state court findings were made without a full and fair hearing or were otherwise suspect. Instead, he believed it allowed federal judges discretion in deciding whether such hearings are necessary depending on individual circumstances of each case. In this particular instance, Justice Rehnquist felt there was no need for further inquiry as the defendant had already been given ample opportunity to present his claims at both state and federal levels.