§ 17.01   Common Law Rules

 

[A]  General Approach – Many states follow the Model Penal Code in requiring proof of mens rea for every element of the offense.  Nevertheless, the common law’s two approaches to mistakes—depending on whether the offense charged is characterized as general-intent or specific-intent—has endured.

 

If the crime is one of strict liability, a mistake of fact is irrelevant.  Otherwise, the first step in analyzing a mistake-of-fact claim in a jurisdiction that follows common law doctrine is to determine whether the nature of the crime of which the defendant has been charge is specific-intent or general-intent.

 

[B]  Specific-Intent Offenses – A defendant is not guilty of an offense if his mistake of fact negates the specific-intent portion of the crime, i.e., if he lacks the intent designated in the definition of the offense, e.g., "knowingly," "negligently," "recklessly."

 

[C]  General-Intent Offenses

 

[1]  Ordinary Approach: Reasonableness – The ordinary rule is that a person is not guilty of a general-intent crime if his mistake of fact was reasonable, but he is guilty if his mistake was unreasonable.

 

[2]  Moral-Wrong Doctrine – On occasion, courts apply the "moral wrong" doctrine, under which one can make a reasonable mistake regarding an attendant circumstance and yet manifest a bad character or otherwise demonstrate worthiness of punishment.  The rule is generally that there is no exculpation for mistakes where, if the facts had been as the defendant believed them to be, his conduct would still be immoral.

 

[3]  Legal-Wrong Doctrine – A less extreme alternative to the moral-wrong doctrine is the "legal-wrong doctrine."  That rule provides for no exculpation for mistakes where, if the facts were as the defendant thought them to be, his conduct would still be "illegal."  Often this means that a defendant possessed the mens rea for committing a lesser offense, but the actus reus was associated with a higher offense.  Under this doctrine, the defendant is guilty of the higher offense in such circumstances.

 

§ 17.02   Model Penal Code

 

[A]  General Rule – Section 2.04(1) provides that a mistake is a defense if it negates the mental state required to establish any element of the offense.

 

[B]  Exception to the Rule – The defense of mistake-of-fact is not available if the defendant would be guilty of another offense, had the circumstances been as he supposed.  In such cases, contrary to the common law, the Code only permits punishment at the level of the lesser offense. [MPC § 2.04(2)]