Brief Background
The Homicide Act 1957 gained Royal Assent on 21 March 1957 and is an Act of Parliament that helped to partially reform the offence of murder in the English common law.
Why was it introduced?
The Royal Commission on Capital Punishment, appointed in 1949, reported in 1953, at a time when the English legal system was considering the creation of different degrees of murder. This was seen by the Commission as impractical and it recommended other changes to the law. Around this period, there were a number of high profile and controversial cases. This included the case of Derek Bentley who was hanged in January 1953 following a murder conviction under the then law of constructive malice and joint enterprise despite it being his 16-year old friend who had killed a police-officer, whilst Bentley was actually under arrest. His conviction was subsequently quashed as unsafe in 1998. Two years after Bentley’s execution, Ruth Ellis was hanged for killing her partner, before diminished responsibility was recognised in English law. In Ellis v R [2003] EWCA Crim 3556, the Court of Appeal considered that her circumstances would probably have raised an issue of diminished responsibility under the later law, but could not determine how a jury would have decided it. Her appeal was dismissed under the law applicable in 1955.
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What was the aim of the Act?
The aim of the Act was multi-faceted. The first goal was to amend the doctrine of constructive malice. Constructive malice enabled the prosecution of a number of high-profile cases and had the potential to cause injustice. The introduction of the Act looked to redress this. Further to this, the aim of the Act was to address the defences that could be made available to those suffering from mental impairment during the course of an act or omission that caused the death of a victim and for those in suicide pacts. A further major aim was to restrict the death penalty to specified categories of murder.
What main changes did it make to the law?
Specifically, the Act abolished the doctrine of constructive malice. This doctrine found that the mental requirement to establish the offence of murder could be assigned to the defendant where a killing occurred in the course or furtherance of certain offences, such as a felony involving violence (e.g. robbery). Moreover, the Act also introduced defences to murder, which was seen as an increasingly necessary step in criminal law cases and would reduce liability for murder to manslaughter where a partial defence was established.
Key Sections
The Homicide Act, section 1 abolished the concept of constructive malice: a killing in the course or furtherance of another offence requires the same express or implied malice aforethought as any other murder. This concerned the mental element of murder, not a break in the chain of causation. The prosecution must prove an intention to kill or cause really serious bodily harm. The Act did not abolish implied or express malice. DPP v Smith [1961] AC 290 confirmed the sufficiency of intent to cause grievous bodily harm, but its objective approach to imputing intention was superseded by section 8 of the Criminal Justice Act 1967. Intention must be determined from all the evidence, rather than necessarily inferred from the natural and probable consequences of the act.
The Homicide Act, section 2 created the partial defence of diminished responsibility. The Royal Commission on Capital Punishment had examined mental difficulties and criminal responsibility, but had called for further inquiry before adopting the Scottish doctrine of diminished responsibility in English law. As originally enacted, the section required an ‘abnormality of mind’, arising from one of the specified causes, which substantially impaired the accused’s mental responsibility for his/her acts or omissions in killing or being a party to the killing. The current test is set out below. Examples under the former law include evidence of depressive illness following prolonged domestic abuse in R v Ahluwalia [1992] 4 All ER 889, where fresh evidence led to a retrial, and post-natal depression together with premenstrual syndrome in R v Reynolds [1988] Crim LR 679, where a manslaughter verdict was substituted on appeal. This defence is not to be confused with the defence of insanity. Insanity requires a defect of reason arising from a disease of the mind such that the defendant did not know the nature and quality of the act, or did not know that it was legally wrong. In the Crown Court it results in the special verdict of not guilty by reason of insanity, rather than a manslaughter conviction.
The Homicide Act, section 3 amended the former partial defence of provocation, including allowing words as well as conduct to be considered and requiring the jury to assess the reasonable person’s response where the issue arose on the evidence. It was repealed when loss of control replaced provocation in England and Wales on 4 October 2010.
The Homicide Act, section 4 provides a partial defence for a person who kills another, or is a party to the other being killed by a third person, in pursuance of a suicide pact between them. A suicide pact is a common agreement between two or more people having as its object the death of all of them, whether or not each is to take his/her own life. The conviction is for manslaughter rather than murder. The defendant must prove, on the balance of probabilities, that he/she acted in pursuance of the pact while having a ‘settled intention of dying’ in pursuance of it. Merely agreeing to another’s death is insufficient. Encouraging or assisting another person’s own suicide is dealt with separately under section 2 of the Suicide Act 1961.
The Homicide Act, sections 5–7 historically restricted the death penalty to listed capital murders and certain repeated murders. The listed categories included murders in furtherance of theft, by shooting or explosion, in resisting arrest or escaping custody, and specified killings of police or prison officers. These provisions were repealed by the Murder (Abolition of Death Penalty) Act 1965, which abolished the death penalty for murder in Great Britain.
The Homicide Act, section 17 provides that the Act does not extend to Northern Ireland. Section 13(1) also excludes Part I, containing sections 1–4, from Scotland; those substantive reforms concern England and Wales.
2026 update
The Homicide Act 1957 remains an important statute in English criminal law, although several of its provisions have been amended by later legislation.
The Act originally introduced key reforms to the law of murder, including the abolition of constructive malice and the creation of partial defences that could reduce murder to manslaughter, most notably diminished responsibility and suicide pact.
However, the defence of diminished responsibility in section 2 was substantially revised by the Coroners and Justice Act 2009. For killings governed by the revised provision, in force from 4 October 2010, the defendant must prove on the balance of probabilities an abnormality of mental functioning arising from a recognised medical condition, which substantially impaired their ability to understand the nature of their conduct, form a rational judgment, or exercise self-control. The abnormality must also explain their conduct by causing it or being a significant contributory factor. A diagnosis alone is insufficient. In R v Golds [2016] UKSC 61, the Supreme Court held that not every impairment beyond the trivial is substantial; the degree of impairment is for the jury to assess. Voluntary acute intoxication alone cannot establish the defence: R v Dowds [2012] EWCA Crim 281.
In addition, the common law defence of provocation, as modified by section 3 of the 1957 Act, was replaced by the statutory partial defence of loss of control under sections 54–56 of the Coroners and Justice Act 2009. It requires a loss of self-control with a qualifying trigger and the statutory comparison with a person of the defendant’s sex and age, with normal tolerance and self-restraint, in the relevant circumstances. Qualifying triggers are fear of serious violence by the victim against the defendant or another identified person, or things said or done of an extremely grave character causing a justifiable sense of being seriously wronged, or a combination, subject to the exclusions in section 55. The loss need not be sudden, but a considered desire for revenge excludes the defence. Once sufficient evidence raises the defence, the prosecution must disprove it beyond reasonable doubt.
Murder carries a mandatory life sentence. A partial defence reduces the conviction to manslaughter, for which life imprisonment is the maximum sentence, rather than an automatic consequence of conviction. As a result, while parts of the Homicide Act 1957 remain in force, the modern law of homicide now operates through a combination of the 1957 Act and later reforms, particularly the Coroners and Justice Act 2009.
Last updated: 11 November 2026
