Legal Definitions - actus reus

In criminal law, actus reus (pronounced ACK-tus RAY-us) refers to the physical act or omission that constitutes a crime. It is the "guilty act" that society seeks to prevent. For an act to qualify as actus reus, it must generally be a voluntary bodily movement. Involuntary actions, such as a reflex or an act performed while unconscious, typically do not satisfy this requirement.

The actus reus can also be an omission, meaning a failure to act. However, a failure to act only qualifies as actus reus if the individual had a legal duty to act. Such a duty might arise from:

• A specific law or statute.
• A contract or agreement.
• A special relationship (e.g., parent-child, doctor-patient).
• Voluntarily assuming care for another person.
• Creating a dangerous situation that then requires intervention.

It is important to distinguish actus reus from mens rea, which refers to the criminal intent or "guilty mind" behind the act. Both elements are usually required for a crime to have occurred.

Here are some examples illustrating actus reus:

• Example 1: Shoplifting

  A person walks into a convenience store, picks up a candy bar, conceals it in their pocket, and then leaves the store without paying. The actus reus in this scenario is the physical act of taking the candy bar, concealing it, and carrying it away from the store without completing the purchase. These are voluntary physical movements that constitute the "guilty act" of theft.

• Example 2: Neglect by a Caregiver

  A professional caregiver is hired to look after an elderly person who requires daily medication. The caregiver, despite being aware of their duty and the patient's need, intentionally withholds the prescribed medication for several days, leading to the patient's severe health deterioration. Here, the actus reus is an omission – the caregiver's deliberate failure to administer the medication. This qualifies as actus reus because the caregiver had a legal and contractual duty to provide care, and their failure to act caused harm.

• Example 3: Vandalism

  During a public protest, an individual picks up a rock and throws it through the window of a nearby building, causing significant damage. The actus reus is the physical act of picking up and throwing the rock, which directly results in the destruction of property. This voluntary action is the "guilty act" that forms the physical basis of the crime of vandalism.