The Legal Elements of an Offence

The general effect of criminal law is to forbid the commission of certain conducts, by creating offenses which could be of commission or omission. In Nigeria, the Criminal Code defines an offense as an act or omission which is rendered punishable under the code or other legislative enactment. But the mere commission of an act or the bringing about of a state of affairs that the law forbids is not enough to constitute an offense. It is generally required that some element of wrongful intent or other fault must exist.

A careful examination of the definition of any particular offense will reveal that it nearly always consists of two elements namely:

1. The physical element; and

2. The mental element

Generally, an offense is an act done or omitted to be done in a particular state of mind. In other words, for there to be an offense there must be an act or omission which takes place in a particular state of mind. Thus, there are two elements that must be present before a crime can be established. English law has evolved two distinctive terms to describe the elements namely:

1. The actus reus (guilty act); and

2. Mens rea (guilty mind)

These two terms have been adopted by the Nigerian legal system and are commonly used and are commonly used in the Nigerian courts to represent the two elements.

ACTUS REUS

The expression “actus reus” is of English law origin. In English law, the expression stands for guilty act. However, the expression can be used in two different senses:

First, it may mean the conduct of the accused person, such as the firing of a fatal shot in the case of murder. It may also mean the event, result or consequence of the conduct, such as the death resulting from the firing of the gun by the accused.

The physical external element or actus reus of an offense has been variously referred to as the act, deed, even or conduct. The precise meaning of “an act” for the purpose of constituting an offense has been quite elusive. However, it is most correct or acceptable to define an act as a willed bodily movement. It is the element of volition that underlies the notion of an act as a condition for criminal liability in law.

Intention on its own, however wicked or dangerous it might be if put into action, is usually not forbidden or punished by the law until the intention is put into execution, or until steps are being taken to put it into execution.

An omission can also form the actus reus of an offense. In common parlance, whether the failure to do something is an omission will depend on whether a person would, in those circumstances, ordinarily be expected to have acted. Where the expectation is recognized and sanctioned by law, it can be said that there is a legal duty to act, failure of which constitutes an omission. In this case, the offense is simply failure to perform a legal duty.

MENS REA

The mental element of an offense is referred to as the Mens rea. Mens rea in English law is used in two rather different senses.

In the first sense, it is used to refer to the mental element which is required to be proved in any particular offense in order to ground criminal liability. In this sense, we talk of the mens rea of particular offenses. For example, the mens rea of stealing, rape assault, etc.

In the second sense, it is used to refer to the principle of statutory interpretation which runs through the English criminal law, which requires that whenever a court is considering the definition of an offense, the court must presume, until the contrary is proved, that the definition requires the proof of guilty mind or mens rea against the accused person. In this sense, this English law principle is usually referred to as "The doctrine of Mens rea", and this forms the basis of the principle of "no liability without fault".