Actus reus and mens rea.

• A. Actus reus is the mental state.
• B. Mens rea is the conduct.
• C. Both actus reus and mens rea are required in most crimes, unless strict liability applies.
• D. Strict liability offenses require no actus reus.

Answer: (C)

The key idea is that criminal liability usually rests on two elements: a prohibited act or omission (the actus reus) and a culpable mental state (the mens rea), and these must typically coincide. In most crimes you need both the physical act and the accompanying fault or intent for liability to attach. There are strict liability offences, where the mens rea element is not required, but the actus reus—actually doing the prohibited act or omission—still must occur. That’s why the statement that both actus reus and mens rea are required in most crimes, unless strict liability applies, is the best answer.

Actus reus is the physical act or omission, not the mental state. Mens rea is the mental state, not the conduct. And while strict liability offenses bypass the need to prove mens rea, they still involve an actus reus.