In the United States v. Marion et al., 1971, the Supreme Court ruled on a case involving the Speedy Trial Clause of the Sixth Amendment. The defendants, Carl Lee Marion and Robert Earl Williams, were indicted in 1965 for several offenses allegedly committed in 1960 but were not arrested until three years after their indictment due to an ongoing investigation into other crimes they may have committed. They argued that this delay violated their right to a speedy trial as guaranteed by the Sixth Amendment. However, the Supreme Court disagreed with them and held that since there was no actual prejudice against them resulting from this delay (i.e., loss of evidence or witnesses), it did not violate their rights under said amendment. The court further clarified that protection under this clause becomes applicable only when a person has been formally accused via either arrest or indictment.

In the dissenting opinion for United States v. Marion et al., Justice Brennan, joined by Justices Douglas and Marshall, argued that the majority's decision to dismiss the defendants' claim of pre-indictment delay violated their Sixth Amendment right to a speedy trial. The dissenting justices believed that this right should extend from when suspicion is first aroused or an investigation begins rather than only after formal charges are filed. They contended that delays before indictment can be just as damaging as those following it, potentially impairing a defendant's ability to prepare an effective defense due to faded memories or lost evidence. Furthermore, they pointed out that such delays could also cause unnecessary anxiety and limit one’s liberty if they were aware of ongoing investigations against them but unable yet to defend themselves in court. Therefore, according to these justices’ perspective, any undue delay in bringing charges should be considered unconstitutional regardless of whether it occurs before or after indictment.