In the 1956 case Mallory v. United States, the U.S. Supreme Court overturned a murder conviction on grounds that a confession had been obtained in violation of Rule 5(a) of the Federal Rules of Criminal Procedure. The defendant, Mallory, was arrested and held by police for approximately eight hours before being presented to a magistrate judge; during this time he confessed to committing murder. The court ruled that his confession should have been excluded from evidence because it was obtained during an unnecessary delay in presenting him before a magistrate after arrest - as required by Rule 5(a). This rule mandates prompt arraignment to prevent law enforcement from detaining suspects for extended periods with the aim of extracting confessions or incriminating statements outside judicial supervision. Therefore, due to this breach in procedure and rights protection, Mallory's conviction was reversed.

In the dissenting opinion for Mallory v. United States, Justice Harold Burton argued that the majority's decision to exclude a confession due to delay in arraignment was not justified by the Federal Rules of Criminal Procedure or precedent cases. He contended that there were no signs of coercion or mistreatment during Mallory’s detention and interrogation, which lasted less than eight hours from arrest to confession. Furthermore, he pointed out that this period included time for meals and rest periods as well as questioning on unrelated crimes. Justice Burton also noted that while prompt arraignment is desirable, it should not be an absolute requirement when other safeguards are present such as legal counsel being available at all times during questioning.