Section 71.04 - Testimonial Immunity(a) A party to an offense under this chapter may be required to furnish evidence or testify about the offense.(b) No evidence or testimony required to be furnished under the provisions of this section nor any information directly or indirectly derived from such evidence or testimony may be used against the witness in any criminal case, except a prosecution for aggravated perjury or contempt.Amended by Acts 1993, 73rd Leg., ch. 900, Sec. 1.01, eff. 9/1/1994.Added by Acts 1977, 65th Leg., p. 922, ch. 346, Sec. 1, eff. 6/10/1977.