This document discusses the concept of actus reus, which is the physical or external element of a crime. It explains that for a crime to occur there must be both an actus reus (physical act) and mens rea (guilty mind). The act must be voluntary - it cannot be something involuntary like sleepwalking. Examples of actus reus include taking property for theft or unlawfully killing for murder. Mere thoughts or status are not enough to constitute an actus reus. Omissions can also qualify as an actus reus if there is a legal duty to act. Possession requires knowing control over an item. The act must also be the factual and proximate cause of the prohibited result for