Kastigar v. United States
United States Supreme Court
406 U.S. 441 (1972)
Kastigar and another witness (defendants) were subpoenaed to testify before a federal grand jury and given immunity under 18 U.S.C. § 6002, which shields the compelled testimony and any evidence derived from it from use in any later prosecution except for perjury or related offenses. The witnesses argued this use-and-derivative-use immunity was narrower than the Fifth Amendment privilege itself and could not lawfully force them to testify; they wanted full transactional immunity from prosecution for any related crime. The district court disagreed and ordered them to testify; when they refused, they were held in contempt. The Ninth Circuit affirmed, and the Supreme Court granted certiorari.
Whether the government may compel testimony from a witness who has invoked the Fifth Amendment by granting immunity from use of the compelled testimony and any evidence derived from it in a later criminal proceeding.