The Act Commentary on Sections Part 2 - Criminal offences Section 54:  Partial defence to murder: loss of control
333.Provocation is a common law partial defence supplemented by section 3 of the 1957 Act. Under the partial defence, a defendant who would otherwise be guilty of murder will be guilty of manslaughter instead if he or she was provoked by things said or done (or both) to lose self-control, and in the opinion of the jury the provocation was enough to make a reasonable person do as the defendant did.
334.Section 56 abolishes the common law partial defence of provocation and replaces it with a new partial defence to murder of “loss of control” at sections 54 and 55.
335.Section 54 sets out the criteria which need to be met in order for the new partial defence of loss of self-control to be successful.
336.Subsection (1) lists those as:
337.Subsection (2) clarifies that the loss of control described in subsection (1) need not be sudden. Under the existing common law partial defence of provocation, the courts have held that the loss of self-control must be sudden. Case law has developed over time to the effect that the partial defence might still apply though where there was a delay between the provocative incident and the killing. The length of time between the incident and the killing does however affect whether there is sufficient evidence of a loss of self-control for the judge to leave the issue to the jury, and how readily a jury accepts that the defendant had indeed lost his or her self-control at the time of the killing. Although subsection (2) in the new partial defence makes clear that it is not a requirement for the new partial defence that the loss of self control be sudden, it will remain open, as at present, for the judge (in deciding whether to leave the defence to the jury) and the jury (in determining whether the killing did in fact result from a loss of self-control and whether the other aspects of the partial defence are satisfied) to take into account any delay between a relevant incident and the killing.
338.Subsection (3) supplements subsection (1)(c) by clarifying that the reference to the defendant’s circumstances in that subsection means all of those circumstances except those whose only relevance to the defendant’s conduct is that they impact upon the defendant’s general level of tolerance and self-restraint. Thus, a defendant’s history of abuse at the hands of the victim could be taken into account in deciding whether an ordinary person might have acted as the defendant did, whereas the defendant’s generally short temper could not. Consequently, when applying the test in subsection (1)(c) the jury will consider whether a person of the defendant’s sex and age with an ordinary level of tolerance and self-restraint and in the defendant’s specific circumstances (in the sense described earlier in this paragraph) might have acted as the defendant did.
339.Subsection (4) ensures that those acting in a considered desire for revenge cannot rely on the partial defence, even if they lose self-control as a result of a qualifying trigger.
340.Subsection (5) clarifies where the burden of proof lies in murder cases where the partial defence is raised. If sufficient evidence of the partial defence is raised, the burden of disproving the defence beyond reasonable doubt rests with the prosecution. It is supplemented by subsection (6) which confirms that for the purposes of subsection (5) the evidence will be sufficient to raise an issue as to the defence where a jury, properly directed, could reasonably conclude that the partial defence might apply. It will be a matter of law, and therefore for a judge to decide, whether sufficient evidence has been raised to leave the partial defence to the jury. This differs from the position with the existing partial defence of provocation where, if there is evidence that a person was provoked to lose his or her self-control, the judge is required by section 3 of the 1957 Act to leave the partial defence to the jury even where no jury could reasonably conclude that a reasonable person would have reacted as the defendant did. Where there is sufficient evidence for the issue to be considered by the jury, the burden will be on the prosecution to disprove it. This is the same burden of proof as other defences, including self-defence.
341.Subsection (7) sets out that, when the defence is successful, the defendant will be guilty of manslaughter instead of murder.
342.Subsection (8) provides that even if one party to a killing is found not guilty of murder on the grounds of the partial defence of loss of self control, this does not affect the position of any other person who may be liable for murder in respect of the killing.