Knowledge

This chapter begins with United States v. Moore, a case from the United States Court of Appeals for the District of Columbia involving a heroin addict charged with drug possession. It describes in more detail what the actus reus and mens rea requirements entail when applied to a defendant who realized he was committing a crime. It discusses, in relation to actus reus, free will as the capacity to choose otherwise, proposes a test to help determine if a defendant lacked the capacity to choose otherwise (the Stephen test), and compares the actus reus requirement to the existing defense of insanity. In relation to mens rea, the chapter explains how the Jekyll test (introduced in Chapter 2) applies to defendants who realized there were committing a crime, and then compares mens rea to the existing defenses of duress and provocation, as well as to the problem of the “willing addict.” It concludes with a discussion of the circumstances under which the state can legitimately ascribe guilt to a defendant who lacked actus reus or mens rea at the time of the crime but whose guilt can nonetheless be traced to a prior guilty act or omission.