431. Self-Defence and Excessive Self-Defence. A person is entitled to use a degree of force to repel an unlawful attack upon himself or another person. However, the degree of force used must bear a reasonable relationship to the danger caused by the attack. In some circumstances a person may need to use extreme levels of violence in self defence, even killing the aggressor if this is necessary. However, in another situation he may only need to use a slight degree of force, or (by withdrawing or retreating) none at all. Where a homicide results from the use of excessive force to repel an attack the defendant may be convicted of either murder or manslaughter. Where the defendant has used a degree of force which is considered excessive, and it is shown that he was aware that the degree of force was greater than was needed to repel the attack, the jury may convict of murder. However, if the defendant believed that the degree of force used was necessary, he is guilty only of manslaughter. In the leading Australian case, Viro v R, the Court drew a distinction between the defendant’s belief as to the prevailing circumstances and his belief as to the degree of force which the situation warranted. In relation to the former, an objective test is applied. The defendant’s belief as to the necessity of defence must be a reasonable one in the circumstances as he believed them to be. In relation to the degree of force the defendant believed necessary a subjective test is applied. The question is whether the defendant actually believed that the degree of force used was necessary under the circumstances. It seems that the effect of Viro’s case is to introduce into the ‘reasonable man’ test an element of subjectivity similar to that which now applies in the law of provocation. As Howard comments:
[T]his formulation is subtly but significantly different from the standard of the reasonable man. Although it requires D’s belief to be reasonable, or perhaps not unreasonable would be nearer the mark having regard to the burden of proof on D, it follows developments in the law of provocation by laying stress on what might have seemed reasonable to the particular person rather than to a fictional abstraction called the reasonable man.
The position with the ‘objective’ test in this context seems therefore to be the same as it is with provocation, in which case the arguments about possible legislative reinforcement or change will be similar.
432. Mistaken Belief. The relevance of mistaken belief to criminal responsibility differs depending on the kind of mistake, and on the offence. A mistake of law is, with certain exceptions, irrelevant: this rule, and the exceptions to it, are discussed below. A mistake of fact as to a particular element of an offence may be relevant in several different ways. It may negative the intent necessary for the offence: for example, if the defendant mistakenly but honestly believed that the victim was consenting to sexual intercourse, the defendant cannot be guilty of rape. There is no requirement in such cases that the defendant’s belief be reasonable, provided it is shown to be genuine. In other cases, there may be no requirement that the defendant believed in the existence (or was reckless as to the non-existence) of particular facts. However at common law it is a defence to most criminal charges that the defendant actually believed on reasonable grounds in the existence of facts which, if true, would have exonerated him from liability. This defence applies especially to regulatory or statutory offences, many aspects of which are (apart from the defence) subject to a regime of strict liability. For present purposes, these offences are however of little or no relevance.
433. Mistake and Aboriginal Customary Laws. Mistaken or ‘unreasonable’ belief can be produced by adherence to a world-view based on traditional or customary beliefs or patterns of behaviour. Adherence to tradition or to customary laws is not to be equated with superstition, but the two may be associated, and when they are legal problems of considerable difficulty arise. For example an American Indian was convicted of manslaughter when he shot what he believed was a Wendigo, an evil spirit in human form. Similar problems have arisen in Papua New Guinea with sorcery, although the courts have refused to entertain defences based, for example, on mistake of fact. Equivalent problems do not seem to have been raised in Australian cases, at least not in the last fifteen years. There are certainly Aboriginal practices of ‘magic’ or ‘sorcery’, but they do not seem to have had much impact in criminal cases. Eggleston suggests that a defence based on mistake may have been available to the defendants in the Skinny Jack case, but it was not in fact raised there. It is unlikely that the defence of honest and reasonable mistake of fact would be directly relevant in cases involving customary law issues. What is more likely is that mistaken assumptions or beliefs based on tradition may affect the defendant’s intent (in cases where mens rea is required), or his belief as to an appropriate response in cases of self-defence or provocation. Given the qualified nature of the ‘objective’ requirement for both defences, appropriate account could probably be taken of customary laws and traditional’ practices in such cases, under the existing law.
434. Honest Claim of Right. As has been seen it is no defence to a criminal charge that the defendant mistakenly believed he had a legal or moral right, or even a duty, to do what he did. Thus a traditional Aborigine may well believe that a particular action is required by his customary laws: that is, in general, no excuse if the act contravenes the general law, though it may be relevant in sentencing. But a defence of claim of right is available in offences involving property. The basis of offences involving property is that a person intends to take or damage property in a manner inconsistent with the rights of the true owner of the property. If the defendant honestly believes that the property belongs to himself, or that he has a justified claim to it, then it is not possible to prove the necessary criminal intent, whether under the common law or the Codes. In particular, there is no requirement that any mistaken claim of right be reasonable, so long as it is honest.
435. Claims of Right under Aboriginal Customary Laws. An example of the way in which the claim of right defence may assist Aborigines acting in good faith under their customary law is R v Craigie and Patten, a case heard in the District Court of New South Wales. Two Aborigines had broken into a private art gallery and taken possession of traditional Aboriginal bark paintings which they believed they had a right to claim for the Aboriginal people. They were charged with breaking and entering in order to steal the paintings. Thus their guilt depended on whether the taking of the paintings was theft. The art in question was traditional art which, it was claimed, under Aboriginal customary laws belongs not to an individual but to the relevant Aboriginal group. The defendants took possession of the paintings in order to prevent them from leaving Australia. Judge Bell indicated to the jury that a claim of right must be founded on the law of New South Wales and not on Aboriginal customary laws. The prosecution had the onus of proving that the defendants ‘did not have an honest belief in the existence of a set of facts which, if it had existed, would have justified their acts according to law, and that means according to the law of New South Wales’. But the defendants claimed that according to the law of New South Wales as well as Aboriginal customary law they were entitled to take the paintings. His Honour continued:
I do not administer the Aboriginal Customary ‘laws’ in this Court, and you are required to bring your verdict in according to the New South Wales law, not according to the law that was in force here before the whites came. But the relevance of what you we re told about those aboriginal customs is a limited one in that, had there been no such evidence, you would have dismissed in the first minutes of the trial any suggestion that either of these people could have believed that what he was doing was lawful. But now each of them is able to say, ‘Under our law the situation was thus, and that is the reason why we believe or believed that the New South Wales law permitted us to do what we did’.
The jury returned verdicts of not guilty in respect of both defendants. Thus it may be that, where an Aborigine honestly believes that Australian law will enforce a right of possession which is recognised by his customary laws, a defence of claim of right will be established. But the defence is not likely to be available as a general form of recognition of honest, though mistaken, claims based on Aboriginal customary laws. It applies only in the case of property offences, which represent a very small proportion of offences where Aboriginal customary laws are involved. It is only available where the defendant can assert an honest belief about the general law, not about Aboriginal customary laws as such. If Aboriginal customary laws are to be a defence to crimes under the general law, they should be a defence as such, not just in those cases where the defendant happens to be mistaken about the relationship between Aboriginal customary law and the general law. No change is therefore desirable, in the context of this Reference, to the defence of claim of right. Whether there should be a customary law defence is considered later in this Chapter.
See generally Howard, 89-94, 137-9; Glanville Williams, 448-76.
(1978) 18 ALR 257.
Howard, 91. cf Viro v R (1978) 18 ALR 257, 302-3 (Mason J), 309-10 (Jacobs J).
See para 441.
See para 416-18.
Thomas v R (1937) 59 CLR 279; Proudman v Dayman (1941) 67 CLR 536; R v Reynhoudt (1962) 107 CLR 381; Howard 363-377. The position is substantially the same in the Code States: Qld, s 24; WA, s 24; Tas, s 14; NT, s 32.
R v Machekequonabe (1894) 28 Ont 309. See Glanville Williams, ‘Homicide and the Supernatural’ (1949) 65 Law Q Rev 491; Howard, 41, 106.
See RS O’Regan, ‘Sorcery and Homicide in Papua New Guinea’ (1974) 48 ALJ 76; Weisbrot (1982) 79-82; and see also the works by RB Seidman, ‘Mens Rea and the Reasonable African: The Pre-Scientific World-View and Mistake of Fact’ (1966) 15 ICLQ 1135, and ‘Witch Murder and Mens Rea: A Problem of Society under Radical Social Change’ (1965) 28 Mod L Rev 46.
cf RM Berndt & CH Berndt, The World of the First Australians, 4th rev edn, Rigby, Adelaide, 1985, 319-335. The only instance is which ‘sorcery’ was mentioned in the cases collected in ACL RP6A was Case No 1, where D was said to feel himself ‘in danger from spirits who would take [his] kidney fat while asleep’: id, 4-5. This was taken into account by Justice Forster in sentencing, but on any view D’s act of manslaughter was wrongful in that case. On this question from a socio-medical viewpoint see J Reid, Sorcerers and Healing Spirits Continuity and Change in an Aboriginal Medical System, ANU Press, Canberra, 1983, esp 92-118; 1H Jones, ‘stereotyped aggression in a group of Australian Western Desert Aborigines’ (1971) 44 Br J Med Psychol 259; 1H Jones & DJ Home, ‘Psychiatric Disorders among Aborigines of the Australian Western Desert’ (1973) 7 Soc Sci & Med 219; JE Lemaire, The Application of Some Aspects of European Law to Aboriginal Natives of Central Australia, LLM thesis, University of Sydney, Sydney, 1971, 118-126; J Cawte, Medicine is the Law, University Press of Hawaii, Honolulu, 1974, esp ch 6. See also LR Hiatt, Kinship and Conflict, ANU Press, Canberra, 1965 119-21 ; WL Warner, A Black Civilisation, Harper & Bros, London, 1937, ch 7, 8; B Spencer and FJ Gillen, The Native Tribes of Central Australia, McMillan, London, 1899, ch 16; DB Rose, ‘Dingo Makes us Human: Being and Purpose Australian Aboriginal Culture’. Phd Thesis, Bryn Mawr College, Bryn Mawr, March 1981, 372-3.
But the Papua New Guinea Supreme Court refused to treat sorcery as giving rise to a defence of provocation: Weisbrot (1982) 79. The Sorcery Act 1971 s 20 expressly allows sorcery to count as provocation, provided the ordinary villager in similar circumstances would have reacted in a similar fashion.
Howard, 367-71; Glanville Williams, 405-15. cf para 415.
Power v Huffa (1976) 14 SASR 337. In Grant v Borg  1 WLR 638, 64 Lord Bridge described this principle as ‘fundamental’. And cf P Brett, ‘Mistake of Law as a Criminal Defence’ (1966) 5 Melb U L Rev 179; AJ Ashworth, ‘Excusable Mistake of Law’  Crim L Rev 652.
For the common law see Howard, 218-9. For the Codes see NT s 30; Qld, s 22; Tas, s 45; WA, s 22.
Unreported, November 1980; see ACL RP 6A, 67-9.
Another case in which claim of right was invoked was R v Holroyd, unreported, Cairns District Court, 1978, where D cut fishing nets which he believed interfered with the use of tribal lands: see W Goss & B Harrison, Submission 273 (7 May 1981) 12.
For a strong application of this principle, in circumstances somewhat analogous to Craigie and Patten, see Police v Minhinnick New Zealand, Rotorua Magistrate’s Court, unreported (Trapski SM) 3 March 1978. But for difficulties with the defence in customary law contexts overseas see CO Okonkwo, ‘The Defence of Bona Fide Claim of Right in Nigeria’ (1973) 17 JAL 271.
See para 442-453.