Can a witness be protected from prosecution if compelled to testify?

Under California law, a witness may not be prosecuted for any act about which he or she was required by the district attorney to testify. ( 1324.) In addition to broad transactional immunity, there is also "use immunity"--"immunity from the use of compelled testimony, as well as evidence derived directly and indirectly therefrom...." (Kastigar v. United States (1972) 406 U.S. 441, 453, 92 S.Ct. 1653, 1661, 32 L.Ed.2d 212.) Use immunity does not afford protection against prosecution, but merely prevents a prosecutor from using the immunized testimony against the witness. Use immunity provides sufficient protection to overcome a Fifth Amendment claim of privilege. Transactional immunity is not constitutionally required. (Ibid.)