Iowa Code
Chapter 701 - GENERAL CRIMINAL LAW PROVISIONS
Section 701.6 - Ignorance or mistake.

701.6 Ignorance or mistake.
All persons are presumed to know the law. Evidence of an accused person’s ignorance or mistake as to a matter of either fact or law shall be admissible in any case where it shall tend to prove the existence or nonexistence of some element of the crime with which the person is charged.
[C79, 81, §701.6]