Actus Reus

So what is Actus Reus?
Actus Reus is the conduct of the accused (The defendant). It can be an act of commission or act of omission, and it must be a voluntary act that causes the damage or harm. It can also be a "state of affairs". * Commission or act of Omission: A person may incur criminal liability for failing to do that which the law requires him to do as much as by doing that which the law prohibits.
The actus reus includes the state of affairs or circumstances surrounding the commission of the offence, together with the results or consequences (if any) that flow from that act or omission. It is essential that the defendant acted voluntarily and that he caused the injury, damage or harm.
In other words, actus reus includes all the elements of the offence indicated in the definition except the mens rea (the state of mind), if any. * Must be a voluntary act: Generally the accused's conduct must be a voluntary act or omission.
The accused will not be held liable for acts done in a state of automatism. Automatism resulting from self-induced intoxication is no excuse. * The accused must cause the prohibited consequences: The crime must be caused by some conduct by the accused.
That conduct need not be a direct cause of the crime, but can be through the agency of others. The conduct need not be the sole or the effective cause of the crime, provided it cannot be dismissed as trivial, or as merely events leading up to the commission of the crime.

* An omission is only culpable if there is a common law or statutory duty to act: Generally there is no obligation on anyone to prevent harm or wrongdoing.

Omissions are only criminal where a duty to act arises at common law or is imposed by statute.

So what is Mens Rea?

Mens Rea is an element of criminal responsibility, a guilty mind; a guilty or wrongful purpose; a criminal intent. Guilty knowledge and wilfulness.

A fundamental principle of Criminal Law is that a crime consists of both a mental and a physical element. Mens rea, a person's awareness of the fact that his or her conduct is criminal, is the mental element, and actus reus, the act itself, is the physical element.

The concept of mens rea developed in England during the latter part of the common-law era (about the year 1600) when judges began to hold that an act alone could not create criminal liability unless it was accompanied by a guilty state of mind. The degree of mens rea required for a particular common-law crime varied. Murder, for example, required a malicious state of mind, whereas Larceny required a felonious state of mind.

Today most crimes, including common-law crimes, are defined by statutes that usually contain a word or phrase indicating the mens rea requirement. A typical statute, for example, may require that a person act knowingly, purposely, or recklessly.

Sometimes a statute creates criminal liability for the commission or omission of a particular act without designating a mens rea. These are called Strict Liability statutes. If such a statute is construed to purposely omit criminal intent, a person who commits the crime may be guilty even though he or she had no knowledge that his or her act was criminal and had no thought of committing a crime. All that is required under such statutes is that the act itself is voluntary, since involuntary acts are not criminal.

Occasionally mens rea is used synonymously with the words general intent, although general intent is more commonly used to describe criminal liability when a defendant does not intend to bring about a particular result. Specific Intent, another term related to mens rea, describes a particular state of mind above and beyond what is generally required.