Two brothers D1 and D2 were jointly charged with the murder of their father, who had seriously ill-treated the younger D2 over a period of eight years while D1 was away from home. Allowing their appeal and substituting a manslaughter verdict, the Court of Appeal said the jury should have been told to consider the father's words and deeds towards D2 when deciding whether or not D1 had been provoked, particularly since D1 had returned home deliberately to protect D2 from his father's violence.
Similarly, the courts had tried in earlier cases to lay down exactly what conduct could and what could not amount to provocation, but the Act set these precedents aside. The defendant can claim provocation where the supposedly provocative behaviour is not unlawful or unreasonable, or where he is mistaken (perhaps through voluntary intoxication) as to the meaning of the other person's behaviour, or even where the supposedly provocative behaviour was in fact a response to his own.
A man D became jealous of his wife W's association with another man S, and threatened to kill him. Over the course of the next six months D broke into W's bedroom with a loaded pistol, set fire to a friend's house, and eventually shot W as she met S outside the library where she worked. D was convicted of murder and appealed on the grounds that the judge's direction to the jury addressed only the possibility of provocation by S himself, and ignored the possibility of provocation by W.
The Court of Appeal said the jury in considering provocation were entitled to look at acts or words emanating from a person other than the victim, but applied the proviso and upheld the conviction. A chronic alcoholic D was very depressed following the departure of a long-time woman friend W, and had become quite drunk. Another friend V, also drunk, made a number of derogatory remarks about W, which so angered D that he battered V some twenty times with a heavy ashtray and killed him. At his trial for murder, D claimed provocation.
The judge told the jury to consider the effect V's drunken remark would have had on a reasonable sober person, and the jury convicted. Dismissing D's appeal, the Court of Appeal said that in ascribing to the reasonable man the characteristics of the defendant, only those characteristics which were reasonably permanent were to be considered, and any special characteristics were to be taken into account only where they related directly to the provocation. Thus "provocative words alluding to some infirmity or deformity …
might well bring about a loss of self-control", but "it would not be sufficient … for the offender to claim merely that he belongs to an excitable race". man D killed his baby, and claimed he had been provoked by its constant crying. Quashing his conviction for murder and substituting a five-year sentence for manslaughter, Stocker LJ said the trial judge was bound by the plain words of the statute to leave this defence to the jury. Provocation need not be unlawful in itself, and a baby's crying was undoubtedly "things done".
A blackmailer A went to V's hotel room in the early hours, after making a series of telephone calls, and pressed V for payment. V responded by swearing at A and attacking him with a knife; A seized the knife from V and stabbed him nearly 30 times, killing him. Allowing A's appeal against his conviction for murder, and substituting manslaughter, the Privy Council said that while a blackmailer should expect a certain amount of retaliation, an attack with a knife was more than might reasonably have been expected and the question of provocation should have been put to the jury.
A man D killed another man V in the course of an argument; he put forward a defence based on self-defence, diminished responsibility and provocation, but was convicted of murder. The Court of Appeal substituted a conviction for manslaughter, and said the judge had been wrong to tell the jury to ignore D's serious clinical depression (which might have reduced his powers of self-control) in considering whether an ordinary man would have acted in such a way.
The House of Lords agreed, and rejected the reasoning of the majority in Luc. Under the 1957 Act, provocation is expressly a matter for the jury and the judge must not tell them to ignore anything they might consider relevant. It is for the jury to determine whether the provocation was enough to cause a reasonable (or ordinary) person, whatever they understand that term to mean, to behave as the defendant did.
The essence of provocation, as set out by Devlin J and approved by the Court of Criminal Appeal in R v Duffy  1 All ER 932, and modified by the Homicide Act 1957, is that some act or series of acts was done by the victim or another, aimed at the defendant or another, which would have caused in any reasonable person and did in fact cause in the defendant a sudden and temporary loss of self-control, rendering him so subject to passion as to make him for the moment not master of his mind.
Two men DD and a woman A had been bullied and terrorised by V over a period up to and including a particular Sunday, and had been unable to obtain police protection. On Wednesday DD and A planned to beat up V the following Sunday and break his arms and legs; this plan was duly carried out, and V died of his injuries. The trial judge withdrew the defence of provocation from the jury, there having been no evidence of any provocative behaviour during the week or at the time of V's death, and DD's conviction was upheld.
After several years of physical and mental cruelty D stabbed and killed her husband and was charged with murder. The trial judge directed the jury that the loss of self-control must have been sudden for provocation to be found, and that a response after D had "cooled down" could not give rise to this defence. D's conviction was upheld by the Court of Appeal. [A second appeal based on new evidence was subsequently allowed.
]A chronic alcoholic killed his girl-friend with an axe while under the influence of alcohol: he admitted the killing but claimed provocation. The Court of Appeal of Jersey allowed his appeal from his conviction for murder and substituted a verdict of manslaughter; the Attorney-General of Jersey appealed against this decision to the Privy Council (not in fact seeking to restore the original verdict, the defendant having already gone through two trials and two appeals, but to clarify the law).
The appeal was heard by a Board of nine judges, all members of the House of Lords, and by 6 votes to 3 the Board disapproved the majority judgment of the House of Lords in Morgan Smith and reaffirmed the decision in Luc Thiet Thuan. Delivering the majority judgment, Lord Nicholls said the majority view in Morgan Smith was inconsistent with the clear language of the statute and was therefore erroneous. The partial defence of provocation involves two elements, one subjective and the other objective.
In determining whether in fact the defendant was provoked, the jury should take into account all the relevant evidence, including evidence of any mental or other abnormality making it more or less likely that he lost his self-control. If the defendant was taunted on account of his intoxication, that may be a relevant matter for the jury to take into account when assessing the gravity of the taunt to the defendant. But in determining (in the language of s.
3 of the Homicide Act 1957) "whether the provocation was enough to make a reasonable man do as he did" the jury must consider the effect of that provocation on a person of the same age and sex as the defendant, but with ordinary powers of self-control. In some cases (such as Morhall) that might mean a glue-sniffer with ordinary powers of self-control, but the jury should not at this point take into account any individual peculiarities such as mental abnormality (which can be more appropriately dealt with through a defence of diminished responsibility) or intoxication.