18 Pa. C.S. § 304 : Consolidated Statutes — CRIMES AND OFFENSES — PRELIMINARY PROVISIONS — CULPABILITY — Ignorance or mistake TEXT PDF Ignorance or mistake as to a matter of fact, for which there is reasonable explanation or excuse, is a defense if: (1) the ignorance or mistake negatives the intent, knowledge, belief, recklessness, or negligence required a establish a material element of the offense; or (2) the law provides that the state of mind established by such ignorance or mistake constitutes a defense. 18 Pa.C.S. § 304 1972, Dec. 6, P.L. 1482, No. 334, § 1, effective 6/6/1973.