Witnesses compelled by
subpoena to appear before a
grand jury are entitled to receive immunity in exchange for their testimony. The grant of immunity impairs the witness's right to invoke the
Fifth Amendment protection against self-incrimination as a legal basis for refusing to testify. Per , a witness who has been granted immunity but refuses to offer testimony to a federal grand jury may be held in
contempt. In addition, grand jury witnesses may be prosecuted for
perjury or
making false statements in their testimony. In
Kastigar v. United States, 406 U.S. 441 (1972), the
US Supreme Court confronted the issue of the type of immunity, use or transactional, constitutionally required to compel testimony. The Court ruled that the grant of use and derivative use immunity is sufficient. Despite
Kastigar, the type of immunity required to compel testimony depends on the law of the applicable jurisdiction. Many states, such as
New York, exceed the requirements of the
US Constitution by requiring transactional immunity to be accorded to compelled witnesses. In states in which defendants have a right to testify on their own behalf at a grand jury proceeding, waiver of immunity is a condition of that right. ==See also==