In the awaken of Miranda v. Arizona, 384 U.S. 436, in which the Court held that certain warnings should be granted before a suspect's declaration made throughout custodial interrogation could be accepted in clues, id., at 479, Congress enacted 18 U.S.C. § 3501 which in essence makes the admissibility of such declarations turn solely on if they were made voluntarily. Petitioner, under indictment for bank robbery and associated government misdeeds, moved to stifle a declaration he had made to the Federal Bureau of Investigation, on the ground he had not obtained “Miranda warnings” before being interrogated. The District Court allocated his ...