378 U.S. 52 (1964), argued 5 Mar. 1964, decided 15 June 1964 by vote of 9 to 0; Goldberg for the Court. The main question before the Court was whether a state may compel a witness to answer questions under an immunity statute when those answers might prove incriminating under federal law. Malloy v. Hogan (1964), decided on the same day, anticipated the Court's answer. Malloy held, for the first time, that the Fifth Amendment's protection against self-incrimination applies to the states through the Due Process Clause of the Fourteenth Amendment.
Having established that the states are now bound by the self-incrimination clause of the Fifth Amendment, the Court in Murphy went on to say that incriminating testimony compelled by one government may not be used by another. Thus federal prosecutors would be prohibited from making any use, direct or derivative, of state-compelled incriminating testimony. Feldman v. United States (1944), which had held to the contrary, was over-ruled.
The privilege against self-incrimination is, of course, not absolute. The effective administration of justice may require the production of incriminating testimony. Immunizing a witness against the use or derivative use of such testimony is one way of obtaining it. But such immunity, said the Court, must be as broad as the privilege itself. If there is any probability that a defendant's testimony, or the fruits thereof, will be used against him even by prosecutors in another jurisdiction, any such proceeding would be constitutionally invalid unless based on evidence obtained wholly independently of the earlier compelled testimony. This is known as “use” immunity.
Use immunity was an issue in Kastigar v. United States (1972) because it did not appear to guarantee absolute protection against a prosecution arising out of the event or transaction in which the witness may have been criminally involved and about which he was forced to testify. “Transactional immunity,” which Kastigar claimed, is far broader than use immunity and would virtually amount to a grant of amnesty. This, said the Court in Kastigar, would exceed the requirements of the privilege against self-incrimination. Use immunity is sufficient and coextensive with the privilege because it places the witness and the prosecution in substantially the same position as if the witness had claimed the privilege.
Donald P. Kommers