A statement of an accused may be used in evidence against him if it appears that the same was freely and voluntarily made without compulsion or persuasion, under the rules hereafter prescribed.
Acts 1965, 59th Leg., vol. 2, p. 317, ch. 722. Amended by Acts 1977, 65th Leg., p. 935, ch. 348, Sec. 1, eff. Aug. 29, 1977.