Actus reus is one of two components of a crime, the other being mens rea. Actus reus refers to the physical component of a crime, the act of committing the crime (physical act of taking something from someone's house).
Mens rea, in contrast, is the mental component of crime, the existence of a criminal intent, and this requires the offender to have intended to carry out the physical act.
Both components are required for conviction under criminal law although for some other laws, called laws of absolute liability, only the physical component is required.
Many criminal lawyers, judges, and professors see the distinction between actus reus and mens rea as one of the more basic of criminal law. Along with the offense-defense distinction, it helps us organize the way we conceptualize and analyze liability. It is said to be the corner-stone of discussion on the nature of criminal liability. The concepts of actus reus and mens rea have justified themselves by their usefulness.
This most basic organizing distinction is not coherent. I suggest that we abandon the distinction in favor of other conceptualizations. - Should the Criminal Law Abandon the Actus Reus-Mens Rea Distinction? - PAUL H. ROBINSON, University of Pennsylvania Law School.
Involuntary manslaughter occurs when the defendant has the actus reus of murder but lacks the mens rea of murder, but it can be proved that the accused had some lesser form of mens rea related to the victim's death. Before the summer of 1993 there were two forms of involuntary manslaughter: constructive manslaughter and Caldwell reckless manslaughter. Constructive manslaughter occurs when the accused has the actus reus of murder and causes the death of the victim while perpetrating another crime. The mens rea for this type of manslaughter is the mens rea for the lesser offense that led to the death. Caldwell reckless manslaughter occurs when the accused has the actus reus of murder and has the mens rea to either see the risk to the victim or where the risk is obvious but the accused gives no thought to it. Now involuntary manslaughter must be reconsidered in the context of the House of Lords decision in R v. Adomako, which approved the Court of Appeal's judgment in the case of R v. Prentice. In these decisions the Caldwell reckless manslaughter does not exist; instead there is gross negligence manslaughter; in order for liability for gross negligence to occur, there must be the actus reus of murder, a risk of death, a duty of care, and a grossly negligent breach of that duty. Recent Developments in the English Law of Involuntary Manslaughter - C Elliott - Journal: European Journal of Crime, Criminal Law and Criminal Justice Volume:3 Issue:3 Dated:(1995)
Identifying the set of necessary and sufficient conditions for an event to be a crime sheds considerable light on the nature of this concept as well as on the purposes of criminal legislation. The application of this method reveals important conception, political, and ethical distinctions between different aspects of the concept of a crime. It reveals inadequacies with well-known distinctions in Anglo-American law, such as the actus reus/mens rea distinction, the objective/subjective distinction, the act requirement/actus reus requirement distinction, the justification/excuse distinction and others. Making this distinction is valuable, insofar as it is a way of bringing intelligibility and organization to the criminal law in general and to criminal codes in particular. This distinction does not gain in intelligibility by appealing to the actus reus/mens rea distinction, or to the act requirement/mens rea distinction, or to the action/culpability distinction of continental criminal law. In order to make a sensible distinction between acts and thoughts, it is necessary to abandon theories that define acts in terms of thoughts. - Philosophical Analysis and the Criminal Law - L.A. ZAIBERT, University of Wisconsin - Parkside - Department of Philosophy.
Assault, Rape, Bigamy,
and Related Offenses; Mens Rea and Actus Reus (From Criminal Law and Approaches
to the Study of Law: Cases and Materials, Second Edition, P 107-228, 1991, John M
Brumbaugh - J M Brumbaugh - Founation Press