Also known as: actus reus · actus reus requirements · guilty act · actus reus element
Written by attorneys · grounded in primary & secondary sources — see below
A foundational principle of criminal liability requiring that guilt rest on a voluntary act or omission of which the actor is physically capable. Reflexes, convulsions, movements during unconsciousness or sleep, and purely involuntary bodily actions are excluded from the category of voluntary acts. Possession satisfies the requirement when the actor knowingly maintains control for a sufficient period to have terminated it.
Austin Abbott and Angela Acosta shake hands after agreeing to divert client funds through altered disbursement sheets. No further steps occur and no documents are prepared. The agreement itself supplies the required voluntary act for common-law conspiracy liability.
Adrian Aguilar observes a worker diverting sludge but consciously hesitates while weighing regulatory options and chooses not to press the alarm. The deliberate decision not to act meets the voluntary-act threshold even though fumes briefly cause dizziness.
Select any source to read its text and confirm it supports the definition.
Amber Alonzo, known to have a seizure disorder, suddenly convulses while adjusting monitoring knobs and disables the alarm system. The reflexive movement cannot supply the voluntary act needed to establish liability for continued discharge.
Aaron Adams dozes at his desk after a double shift and, while asleep, flips a valve that increases downstream discharge. The bodily movement during unconsciousness falls outside the voluntary-act category and cannot support criminal liability.
Arthur Abrams discovers locked barrels of banned waste, holds the access keys, and maintains awareness of his control for several weeks without reporting or terminating possession. The sustained awareness of control satisfies the voluntary-act requirement for possession.
Alliance Holdings employees who lack permanent housing are cited under an ordinance criminalizing sitting or sleeping on public sidewalks. The ordinance targets a status rather than any voluntary act and therefore fails to satisfy the actus reus requirement.
Yes. Under the traditional common-law definition the agreement itself constitutes the culpable act, and the prosecution need not prove any additional overt act.
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Possession satisfies the requirement when the actor knowingly procured or received the item or was aware of control for a sufficient period to have terminated possession.
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No. Bodily movements during unconsciousness or sleep are expressly excluded from the definition of a voluntary act.
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No. Reflexes and convulsions are categorically excluded from the voluntary-act category.
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No. The actus reus requirement demands a voluntary act or omission. Laws that criminalize status alone violate the principle.
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…Colum. L. Rev. 827, 834–835 (1977); cf. Powell v. Texas , 392 U.S. 514, 535–536 (1968) (plurality opinion) (the “doctrines of actus reus , mens rea , insanity, mistake, justification, and duress” are a “collection of interlocking and overlapping concepts which the common law has utilized to assess the moral accountability…