Actus Reus in UK Law

(2) is an aggravating circumstance which adds to the gravity of the actus reus which is defined in the first part of that subsection. Although the proof of that additional element will often involve evidence as to possible or actual danger to life, the additional aggravating factor lies in the mind. That being so, evidence of intoxication is relevant as one of those matters to be taken into consideration in determining whether or not the necessary mental element existed.

(a) The Crown is required to prove the ingredients which constitute the actus reus of the crime. Although different language is used to describe this concept, for present purposes, we respectfully adopt the suggestion in Smith & Hogan, Criminal Law, 8th Edition, at page 28, that it must be shown that the defendant:

They do not provide, as they might have done, that the Eagleton test is to be followed or that, as Lord Diplock suggested, the defendant must have reached a point from which it was impossible for him to retreat before the actus reus of an attempt is proved. On the other hand the words give perhaps as clear a guidance as is possible in the circumstances on the point of time at which Stephen's "series of acts" begin. When that is will depend of course upon the facts in any particular case.

Section 2 of the 1957 Act only comes into play where all the ingredients of murder are established against the defendant. Section 2 of the 1957 Act only comes into play where all the ingredients of murder are established against the defendant.

In the crime of manslaughter, the actus reus is causing the death of another. That actus reus is rendered criminal if it occurs in one of the various circumstances that are prescribed by law. Anyone guilty of manslaughter has, ex hypothesi, caused the death of another by criminal conduct. It is in such circumstances that the rule against forfeiture applies.

The purpose of section 4A, in my opinion, is to strike a fair balance between the need to protect a defendant who has, in fact, done nothing wrong and is unfit to plead at his trial and the need to protect the public from a defendant who has committed an injurious act which would constitute a crime if done with the requisite mens rea.

Of course, a necessary ingredient of the crimes of murder and manslaughter is that the accused has by his act caused the victim's death. Even where it is necessary to direct the jury's minds to the question of causation, it is usually enough to direct them simply that in law the accused's act need not be the sole cause, or even the main cause, of the victim's death, it being enough that his act contributed significantly to that result.