In Australia, self defence is invoked as a legal defence in the cases of murder, manslaughter and assaults.
The accused in invoking the doctrine of self defence must be able to fulfil both the objective and subjective tests. He must prove that the use of force is necessary and objectively as well as subjectively reasonable. However, when the prosecution disproved the contentions of the accused beyond reasonable doubt, his plea of self-defence will fail.
The use of force by the accused in the commission of the offence charged can be subdivided into two aspects: the decision to use the force and the quantum of force to be used. The decision to employ force pertains to the evaluation of the situation demanding the use of force and the amount of force employed.
This means that in the commission of offences below the category of homicide, the accused can act in response to the violence committed against him. However, resort to excessive force as an answer to a mild threat or assault will not be considered a self-defence.
When the offence is murder, it is understood of course that a mere threat would justify the person to employ force of a serious nature to repel the violence to be inflicted upon his person by the assailant. Nonetheless, the court has not specified the threshold of force to be used in this context.
The attack or peril faced by the accused must not necessarily be unlawful in order to justify his act of self-defence. He may, in rare cases acted on a reasonable and mistaken belief that the attack is unlawful, although the same is lawfully committed by the other person.
Disclaimer : This article is just a summary of the subject matter being discussed and should not be regarded as a comprehensive legal advice for you to defend yourself alone. If you are charged with criminal offences, it is recommended that you seek legal assistance from criminal lawyers.