Mistake of Fact

Mistake of Fact: a defense when ∆'s mistaken belief about a fact negates the mens rea required for the offense.

  • General intent crimes (CL): mistake must be honest and reasonable.
  • Specific intent crimes (CL): mistake need only be honest (even unreasonable) — it can negate the specific intent.
  • Strict liability crimes: mistake of fact is no defense, because no mens rea is required.
  • MPC § 2.04(1): mistake is a defense if it negates the mental state required for any element of the offense.
    • Exception: if ∆ would still be guilty of a lesser offense had the facts been as ∆ believed, ∆ is convicted of that lesser offense.

Cases here: