In any trial or hearing in which the mental condition of the defendant is an issue, witnesses not specially trained in psychiatry or psychology may testify as to their observation of the defendant's actions and conduct, and as to conversations which they have had with him bearing upon his mental condition, and they shall be permitted to give their opinions or conclusions concerning the mental condition of the defendant.
Source: L. 72: R&RE, p. 229, § 1. C.R.S. 1963: § 39-8-109.