Actus Reus
Literal meaning: “Guilty act.”
What does the Latin term "Actus Reus" mean in law?
Actus reus is the physical element of a crime — the voluntary act, omission (where a legal duty to act exists), or state of possession that constitutes the prohibited conduct. A fundamental principle of criminal law holds that a person cannot be punished for mere thoughts; there must be a voluntary physical act or a culpable failure to act. The actus reus requirement ensures that criminal liability attaches only to conduct, not to status or involuntary movements. Under the Model Penal Code, an act is voluntary if it is a product of the actor's effort or determination, excluding reflexes, convulsions, and movements during unconsciousness or sleep.
Source: Criminal · Legal Latin
Legal Definition
Actus reus is the physical element of a crime — the voluntary act, omission (where a legal duty to act exists), or state of possession that constitutes the prohibited conduct. A fundamental principle of criminal law holds that a person cannot be punished for mere thoughts; there must be a voluntary physical act or a culpable failure to act. The actus reus requirement ensures that criminal liability attaches only to conduct, not to status or involuntary movements. Under the Model Penal Code, an act is voluntary if it is a product of the actor's effort or determination, excluding reflexes, convulsions, and movements during unconsciousness or sleep.
How It's Used
Actus reus is paired with mens rea as the two foundational elements of every crime. It is discussed in criminal law courses when analyzing whether the defendant engaged in a voluntary act that satisfies the elements of the charged offense. Omissions can constitute actus reus only where the defendant had a legal duty to act.
Example Sentences
The actus reus of larceny is the taking and carrying away of the personal property of another.
The defendant argued that the act was involuntary — a reflex — and therefore could not constitute the actus reus of the crime.
An omission may serve as actus reus when the defendant has a legal duty to act, such as a parent's duty to care for a child.