Colo. Rev. Stat. § 18-16-101
The general assembly hereby finds and determines that illicit traffic in stolen valuable articles is encouraged by the absence of any required record-keeping system by persons purchasing such valuable articles. The general assembly further finds that law enforcement officials are hindered in the identification and recovery of stolen valuable articles, and that law enforcement officials are hindered in the discovery and identification of persons selling stolen valuable articles due to the absence of such a required record-keeping system. Accordingly, it is the intent of the general assembly, by enacting this article, to aid law enforcement officials in the discovery and identification of sellers of stolen valuable articles and in the identification and recovery of stolen valuable articles by providing a mandatory record-keeping and reporting system by purchasers and by providing a holding period during which time such articles shall not be disposed of or altered in any manner. Local governments may adopt ordinances more strict than the provisions of this article.
C.R.S. § 18-16-101