ABSTRACT
Each of the nine Australian jurisdictions-the six states, the two territories and the federal jurisdiction-has its own criminal law. The common law, derived from England, is the main source of criminal law in the three largest jurisdictions. Defences falling into this category include intoxication, insanity, and mistake. However, in relation to murder where the accused uses excessive self-defence, the offence is reduced to manslaughter in New South Wales, South Australia, Western Australia, and Victoria. Thus, while the test in Australia in not uniform, it applies relatively broadly in that it can justify lethal force; it applies to the defence of property and also to the defence of other persons. The key criminal defences in Australia in terms of those which have been subject to the most judicial and legal analysis and which have are more regularly invoked. Hence automatism, insanity, intoxication, and mistake constitute criminal defences because they negate individual culpability.
