We take one great principle of the common law to be, that though it sanctions the defence of a man’s person, liberty and property against illegal violence, and permits the use of force to prevent crimes, and to preserve the public peace, and to bring offenders to justice, yet all this is subject to the restriction that the force used is necessary; that is, that the mischief sought to be prevented could not be prevented by less violent means; and that the mischief done by, or which might reasonably be anticipated from the force used is not disproportioned to the injury or mischief which it is intended to prevent.
5.7Self-defence was first codified in New Zealand in the Criminal Code Act 1893, which enacted the provisions drafted by the English Royal Commission. Self-defence was divided into three provisions applying to self-defence against provoked assaults, unprovoked assaults and defence of a person under protection. These provisions were re-enacted in the Crimes Act 1908 and again, largely unmodified, in the Crimes Act 1961.
Briefly, such a provision will require no abstruse legal thought and no set words or formula to explain it; and only common sense is needed for its understanding. The jury will decide the question of reasonableness in the light of the Judge’s summing up of the evidence. In summing up, the Judge will no longer be faced with varying statutory tests and distinctions that are extremely difficult, if not impossible, to explain simply to a jury.
The Judge will in any case sum up to the jury on the evidence relating to such matters as the degree and mode of force used or threatened by the original aggressor or used in his own defence by the accused, the danger apprehended by the accused, and his opportunity (if any) to avoid the original assault or prevent it by other means. But to list such things in the legislation as matters to which the Court must have regard is in our view unwise and unhelpful in relation to self-defence, where the question is one of fact to be decided in the light of an infinite variety of circumstances in different cases. It might well introduce into the law complexities of interpretation, resulting in a further body of case law and the risk of elevating evidentiary principles into rules of law.