What term describes the guilty act element of a crime, including an action taken or a failure to act?

• A. Mens rea
• B. Actus reus
• C. Concurrence
• D. Causation

Answer: (B)

Actus reus is the physical component of a crime—the actual act or an omission to act when there is a legal duty. It captures what the person does or fails to do, not what they intend. This element ensures there is observable conduct that violated the law. If someone acts by striking another, that is actus reus; if a person has a duty to act and fails to do so, that omission can also satisfy actus reus. This is distinct from mens rea, which concerns the guilty mental state behind the conduct. It also sits with concurrence, the idea that the mental state must accompany the act, and causation, the link between the conduct and the resulting harm. Therefore, the term describing the guilty act element, including action or failure to act, is actus reus.