Special Mens Rea Rules

This section collects various special mens rea rules, either in the context we have already considered, such as mistake-of-fact, or entirely new contexts.

First, we will consider strict liability.

Second, we will consider the defense of mistake of law. This differs from a mistake of fact defense--please pay careful attention to the difference. In the latter, a person might not realize they are within 500 feet of a school--mistake of fact. For the former, they may not realize that it is even a crime to be within 500 feet of a school. This latter, mistake of law, is usually not a defense, but we will see below when it can be.  

Third, we will consider mistake of other law, which sounds like mistake of law but is sometimes more like mistake of fact. Keep in mind what distinguishes mistake of law from mistake of other law. 

Finally, we consider a new mens rea term in federal criminal law: "willfulness." This term does create an actual ignorance of law defense--ignorance or mistake about the law under which the person is charged. Usually, ignorance of the law, that is, unawareness that a law prohibits a person's conduct, is not a defense.