C.R.S. § 39-22-621
The effective date for amendments made to this section by chapter 216, L. 77, was changed from July 1, 1978, to April 1, 1979, by chapter 1, First Extraordinary Session, L. 78, and was subsequently changed to July 1, 1979, by chapter 157, § 23, L. 79. See People v. McKenna, 199 Colo. 452, 611 P.2d 574 (1980).