Without being placed in custody or receiving Miranda warnings, petitioner voluntarily answered the questions of a police officer who was investigating a murder. But petitioner balked when the officer asked whether a ballistics test would show that the shell casings found at the crime scene would match petitioner's shotgun. Petitioner was subsequently charged with murder, and at trial prosecutors argued that his reaction to the officer's question suggested that he was guilty. Petitioner claims that this argument violated the Fifth Amendment, which guarantees that “[n]o person ... shall be compelled in any criminal case to be a witness against himself.”
Petitioner's Fifth Amendment claim fails because he did not expressly invoke the privilege against self-incrimination in response to the officer's question. It has long been settled that the privilege “generally is not self-executing” and that a witness who desires its protection “ ‘must claim it.’ ” Minnesota v. Murphy, 465 U.S. 420, 425, 427, 104 S.Ct. 1136, 79 L.Ed.2d 409 (1984) (quoting United States v. Monia, 317 U.S. 424, 427, 63 S.Ct. 409, 87 L.Ed. 376 (1943)). Although “no ritualistic formula is necessary in order to invoke the privilege,” Quinn v. United States, 349 U.S. 155, 164, 75 S.Ct. 668, 99 L.Ed. 964 (1955), a witness does not do so by simply standing mute. Because petitioner was required to assert the privilege in order to benefit from it, the judgment of the Texas Court of Criminal Appeals rejecting petitioner's Fifth Amendment claim is affirmed....