James Grant

In order to understand the defence of Oscar Pistorius to the charge of murder against him, it is necessary to have reference to the general requirements of criminal liability (see the overview on this site). In particular, one must have reference to the requirement that the fault requirement of criminal liability must extend or relate to all the essential requirements of the unlawful conduct requirement. In the case of murder, the fault requirement is intention and the unlawful conduct requirement is the ‘unlawful killing of another human being’. It is worth observing that intention is an entirely subjective enquiry – it turns on the actual subjective mental state of the accused. One can only be convicted of murder in South Africa, if you intend not only to kill another human being, but if you intend to unlawfully kill another human being. This is a well-entrenched defence in South African law.
One must be careful though that there are subtle differences between claiming that one has not acted unlawfully, and claiming not to have realised one was acting unlawfully.
A claim that one did not act unlawfully is, of course, a claim to have acted lawfully. One may make such a claim if one raises a ground of justification. Self or private defence is the most well-known ground of justification. To succeed with a claim of self or private defence, one must satisfy a number of specific requirements. These requirements can be divided into those which relate to the attack, and those that relate to the response. The requirements of the attack are as follows:
1)      One must be under an unlawful attack;
2)      Which has commenced or is imminent;
3)      Against a legally protected interest – such as life, bodily integrity, or property (of significant value), or the life, bodily integrity, or property of another.
The requirements of the defence are as follows:
4)      Force used in response must be directed at the attacker (and no-one else);
5)      Force must be necessary;
6)      The extent of force must be necessary and reasonable.
If one satisfies these requirements, one’s conduct is lawful and one escapes liability. If one does not satisfy all of these requirements one’s conduct is unlawful. This is, of course, the position for Pistorius – who has conceded as much. There was no unlawful attack upon him or Reeva.
However, one is only ultimately liable, if, as required (see overview under ‘Fault’), one’s fault (intention for murder) extends or relates to all the requirements of the unlawful conduct. If one did not intend to act unlawfully, one has a valid defence. Thus – and this is what Pistorius appears to be claiming – if one mistakenly believes that one was acting lawfully, in self/private defence, one has a valid and complete defence. Here is the catch – actually, there are two.
Firstly, Pistorius will have to convince a court that he genuinely believed that he was acting in self/private defence. The problem he may face is that our law takes a wide view of ‘intention’ – it regards the foresight of a possibility and reckless persistence in the face of that risk, as intention. An accused who foresees the possibility that one or more of the requirements of private defence may not be satisfied, who reconciles to that risk and persists despite the risk, will be held to have intention in our law. Not only would such an accused have acted unlawfully, but s/he will have intended to act unlawfully – merely by the foresight of a possibility that one of the requirements of self/private defence may not be satisfied, and to have persisted despite this risk. For Pistorius, this means that, having conceded that he acted unlawfully, if the state can show that he foresaw the possibility (and reconciled himself to the risk) that he was not under attack, that any supposed attack had not actually commenced and was not imminent, or that no legally protected interest was truly under threat, he may be regarded as having intended to act unlawfully and can be convicted of murder. Alternatively, even if Pistorius was genuinely mistaken in respect of all of the requirements of the attack, he may also be convicted of murder if he foresaw the possibility that one of the requirements of the response may not have been satisfied. He can be convicted of murder if the state can show that he foresaw the possibility (and reconciled himself to that risk) that he was not acting against the supposed attacker, that force was not necessary, or that the extent of force used was not necessary and reasonable.
The second catch is that even if Pistorius succeeds in his defence (of mistake as to unlawfulness) against the murder charge, the next automatic question will be whether this mistake was a reasonable one. This is the question of culpable homicide. It is judged objectively – whereas intention is judged subjectively.  The objective standard of the reasonable person is the basis on which our courts judge negligence. At its essence it is a hypothetical comparison of the actual conduct of the accused against what a reasonable person, in the circumstances of the accused, would have done. If there is any deviation on the part of an accused from what the reasonable person would have done, the accused will be judged to have acted negligently. It is worth noting that our law is only prepared to take account of the immediate external circumstances of an accused – and to hypothetically place the reasonable person in these circumstances. Our law has steadfastly refused to take account of any subjective factors peculiar to an accused, including any disability that the accused suffers with. This has been controversial, but it has been a line from which our courts have not wavered.  If the reasonable person would not have made the mistake Pistorius claims to have made, even if the court accepts that Pistorius made this mistake, he may be convicted of culpable homicide.