Murder is the most serious criminal offence in English law. It carries a mandatory life sentence, meaning the judge has no discretion over the type of punishment. Understanding what constitutes murder is essential because many other offences are defined by reference to it, and the defences available to murder reduce the charge to manslaughter. If you are advising a client charged with murder, you need to understand every element of the offence because the stakes could not be higher.
Murder has never been defined by statute. It is a common law offence, meaning its definition has been developed by judges over centuries through case law. This is unusual for such a serious offence. Despite numerous Law Commission reports recommending a statutory definition, Parliament has never enacted one. You need to know the common law definition inside out because it is the foundation for everything else in this topic.
Murder is the unlawful killing of a reasonable person in being and under the King’s peace, with malice aforethought. That single sentence contains five separate elements, each of which the prosecution must prove beyond reasonable doubt. If any one element is missing, the offence is not murder. Let’s break each one down.
When you see a murder question in the SQE, work through each element systematically. Start with the actus reus (was there an unlawful killing?) and then move to the mens rea (was there malice aforethought?). If any element fails, the charge cannot be murder — though a lesser offence like manslaughter may apply.
A killing is unlawful if it is not justified or excused by law. This means that if the killing was done in self-defence, or by a police officer acting lawfully in the execution of their duty, or by a soldier killing an enemy combatant in the course of armed conflict, then it is not murder. The prosecution must prove that the killing fell outside any lawful justification or excuse. Most killings you encounter in practice will be unlawful, but you should always check.
It is not enough to show that the victim died. The prosecution must also prove that the defendant’s actions caused the death. Causation has two limbs: factual causation (the "but for" test) and legal causation (the "operating and substantial cause" test). Both must be satisfied. If someone else’s act broke the chain of causation, or if the victim’s own actions did so, the defendant may not be liable for murder.
The victim must be a "person in being," which means a human being who has been born alive. A foetus is not a person in being, so killing an unborn child is not murder — though it may be another offence such as child destruction under the Infant Life (Preservation) Act 1929. The critical question is whether the child was born alive, meaning it was breathing independently of the mother. In R v Catt, the court held that a child who breathed after birth, even briefly, was a person in being.
In R v Catt, the defendant attacked a woman who was in the advanced stages of pregnancy. The child was born alive but died shortly after from injuries caused by the attack. The defendant was convicted of murder because the child had been born alive (it breathed independently) before dying from the injuries. This case confirms that the born alive rule focuses on independent breathing, not on viability or how long the child survived.
What happens when a victim is on life support? The courts have held that a person remains alive until brain stem death has been confirmed. In R v Malcherek, the defendant stabbed his wife and she was placed on a life support machine. The doctors later switched off the machine after confirming brain stem death. The court held that the defendant’s actions had caused the death because the victim was still alive (brain stem not yet dead) when the defendant attacked her. The withdrawal of life support did not break the chain of causation.
If brain stem death has already occurred before the defendant acts, then there is no "person in being" to kill. However, if the defendant attacks someone who is critically ill but not yet brain dead, and the victim subsequently dies, the defendant can still be liable for murder. The timing of death is determined by medical criteria, not by when life support is withdrawn.
The requirement that the victim be "under the King’s peace" is an ancient element of the definition. It originally meant that the killing was not committed during a time of war against an enemy combatant. In practice, this element is rarely in issue today. Almost everyone in England and Wales is under the King’s peace at all times. The main exception is the killing of an enemy combatant during armed conflict, which is governed by international law rather than domestic criminal law.
The first step in establishing causation is the factual cause test, also known as the "but for" test. You ask: but for the defendant’s actions, would the victim have died when they did? If the answer is no — the victim would not have died but for what the defendant did — then the defendant factually caused the death. This is usually straightforward, but problems arise when there are multiple causes.
Where two or more acts combine to cause death, the "but for" test can still be satisfied. If both acts were independently sufficient to cause death, then each defendant is liable. For example, if D1 and D2 each give V a separate, lethal dose of poison, and both doses contribute to V’s death, then both D1 and D2 are factually responsible because but for each dose, V would not have died when they did. Even if neither dose alone would have been fatal, both defendants can still be liable if the combined effect was.
Even if factual causation is established, the defendant’s act must also be the legal cause of death. The test is whether the defendant’s act was an "operating and substantial cause" of the death. This means the defendant’s contribution must have been more than merely trivial or insignificant. The act does not need to be the sole or even the main cause — it just needs to be a substantial contribution to the result.
An intervening act by a third party can break the chain of causation, meaning the defendant is no longer legally responsible for the death. However, the courts take the view that the chain is only broken if the intervening act is truly independent and unforeseeable. If the intervening act is a natural consequence of the defendant’s actions (for example, medical treatment for the injuries the defendant caused), it will not normally break the chain.
In R v Smith, a soldier was stabbed during a fight in a barracks. He was carried to the medical centre on a stretcher, but along the way he was dropped. The medical officer gave improper treatment (he pumped the victim’s chest in a way that may have worsened his condition). The victim died. The Court of Appeal held that the defendant was still liable for murder. The medical treatment, even if negligent, was not so abnormal as to break the chain of causation. The original stab wound was still the operating and substantial cause of death.
As a general rule, even negligent medical treatment will not break the chain of causation. The courts recognise that victims of crime often need medical attention, and it would be unfair to let defendants escape liability because doctors made mistakes. The exception is where medical treatment is so grossly negligent or deliberately harmful that it becomes a novus actus interveniens (a new intervening act).
In R v Malcherek, the defendant stabbed his wife, causing severe brain injuries. She was placed on a ventilator. Tests showed brain stem death, and after consulting with the victim’s family, the doctors switched off the ventilator. The defendant argued that the doctors had caused the death by turning off the machine. The Court of Appeal held that the defendant’s stabbing was the operating and substantial cause of death. The withdrawal of life support was not an independent intervening act — it merely allowed the natural consequence of the defendant’s actions to take effect.
In R v Blaue, the defendant stabbed a young woman. She was told she needed a blood transfusion to save her life, but as a Jehovah’s Witness she refused on religious grounds. She died as a result. The defendant argued that her refusal of treatment broke the chain of causation. The Court of Appeal disagreed, applying the "thin skull rule" (also called the "eggshell skull rule"). You must take your victim as you find them. The victim’s refusal of treatment was a foreseeable consequence of her personal beliefs, and the defendant’s actions were still the operating and substantial cause of death.
The thin skull rule means that a defendant cannot argue that the victim’s death was caused by the victim’s own vulnerability. If you stab someone who has a haemophilia condition and they bleed to death, you are still guilty of murder. If you stab someone who refuses medical treatment for religious reasons and they die, you are still guilty of murder. The defendant must take the victim as they find them.
The common law "year and a day rule" provided that no person could be convicted of murder if the victim died more than a year and a day after the injury was inflicted. This rule was abolished by the Law Reform (Year and a Day Rule) Act 1996. Now, there is no time limit — a defendant can be prosecuted for murder even if the victim dies many years later, provided the Attorney General consents to the prosecution.
The year and a day rule was increasingly problematic because advances in medical technology meant that victims could be kept alive on life support for long periods. It was also criticized because a defendant who poisoned someone with a slow-acting substance could escape murder charges if the victim survived for more than a year. The 1996 Act removed this anomaly, though the requirement of Attorney General consent for late prosecutions acts as a safeguard against unfairness.
Despite the word "aforethought," malice aforethought does not require premeditation or planning. It simply means the defendant had the required mental state at the time of the killing. There are two ways to establish malice aforethought for murder: (1) the defendant intended to cause death (direct intent), or (2) the defendant intended to cause grievous bodily harm (GBH) (oblique intent). The defendant does not need to have intended death in every case — intending really serious harm is enough.
In R v Vickers, the defendant broke into a house and was confronted by the elderly owner. He hit her with a cosh and a bottle, causing serious injuries from which she died. The defendant argued that he had not intended to kill her. The Court of Appeal held that the mens rea for murder included an intention to cause grievous bodily harm, not just an intention to kill. This is a fundamental principle: if you intend to cause really serious injury and the victim dies as a result, you are guilty of murder even though you did not want the victim to die.
In R v Cunningham, the defendant went to a house to demand money. He produced a razor and slashed the victim’s throat. The victim died. The House of Lords confirmed that an intention to cause grievous bodily harm is sufficient mens rea for murder. Lord Edmund-Davies described GBH as meaning "really serious bodily harm." The defendant need not have intended to kill — it is enough that he intended to cause really serious injury.
| Feature | Direct Intent | Oblique Intent |
|---|---|---|
| Definition | D desires death or GBH as the purpose of their action | D does not desire death but foresees it as a virtually certain consequence |
| Focus | What D wanted to happen | What D knew would almost certainly happen |
| Example | D shoots V in the head at point-blank range, intending to kill | D plants a bomb in a building, knowing anyone inside will almost certainly die |
| Evidence | Usually straightforward — D’s actions speak for themselves | Requires inference from foresight of virtual certainty |
| Status | Clearly satisfies malice aforethought | Foresight is evidence of intent, not intent itself (Woollin) |
| Key case | R v Mohan (1976) | R v Woollin (1999) |
In R v Moloney, the defendant had been drinking with his stepfather. They had a competition to see who could load a shotgun faster. Moloney loaded his gun and shot his stepfather dead. He claimed he had not intended to kill. The House of Lords gave important guidelines for juries. First, was death or GBH a natural consequence of what D did? Second, did D intend that consequence? The jury should not focus on whether D foresaw the consequence, but on whether D intended it. Foresight of consequences is not the same as intending them, though it is evidence from which intent may be inferred.
In R v Hancock and Shankland, two miners pushed a concrete block from a bridge onto a road during a strike, intending to block the road. The block hit a taxi driver, killing him. The defendants claimed they had not intended death. The House of Lords refined the Moloney guidelines, making clear that the probability of death is an important factor. The greater the probability of the consequence, the more likely it is that the consequence was intended. Foresight of death is not intent, but it is the most important evidence from which a jury may find intent.
In R v Woollin, the defendant lost his temper and threw his three-month-old baby onto a hard surface. The baby suffered head injuries and died. The defendant claimed he did not intend to kill or cause serious harm. The House of Lords held that where the jury are sure that D foresaw death or GBH as a virtual certainty, they may find that D intended that result. The word "may" is important — foresight of virtual certainty does not automatically mean intent, but it entitles the jury to find intent. This is the current law on oblique intent.
The Woollin direction is: where the defendant foresaw death or GBH as a virtual certainty (barring some unforeseen intervention), the jury are entitled to find that the defendant intended that result. Note the word "entitled" — the jury may find intent but are not required to. Foresight of virtual certainty is evidence of intent, not intent itself. This is a fine distinction but it matters in marginal cases.
In R v Matthews and Alleyne, the defendants pushed a drunk man into a river, knowing he could not swim. He drowned. The Court of Appeal confirmed Woollin and clarified the direction. The jury must first decide whether D foresaw death or GBH as a virtual certainty. If they are sure of this, they then go on to consider whether, in all the circumstances, they should find that D intended death or GBH. The two-stage process is: (1) was death/GBH virtually certain? (2) did D intend it?
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Section 1 of the Murder (Abolition of Death Penalty) Act 1965 provides that a person convicted of murder shall be sentenced to imprisonment for life. The sentence is mandatory — the judge has no discretion to impose any other sentence. This is one of the few mandatory sentences in English criminal law, and it has been widely criticised.
A life sentence does not necessarily mean the defendant will spend the rest of their life in prison. The judge sets a minimum term (sometimes called a "tariff"), which is the minimum number of years the defendant must serve before they can be considered for release by the Parole Board. The defendant will only be released if the Parole Board is satisfied that it is safe to do so. Even after release, the defendant remains on licence for the rest of their life and can be recalled to prison at any time.
Schedule 21 of the Criminal Justice Act 2003 sets out the framework for determining the minimum term for murder. It provides starting points based on the seriousness of the offence, which the judge can adjust up or down depending on aggravating and mitigating factors. The starting points are not mandatory — they are guidelines, but judges must have regard to them and explain if they depart from them.
| Starting Point | When It Applies | Minimum Term |
|---|---|---|
| Whole life order | Exceptionally serious cases (e.g. multiple murders, murder of a child involving abduction, murder of a police officer) | Never released |
| 30 years | Murder of a child, murder involving sexual or sadistic conduct, murder for gain, murder of two or more persons | 30 years |
| 25 years | Murder using a knife or other weapon carried to the scene for that purpose | 25 years |
| 15 years | Other murders not falling into the above categories (the default starting point) | 15 years |
A whole life order means the defendant will never be released from prison. These are reserved for the most serious cases. The European Court of Human Rights has held that whole life orders are compatible with Article 3 ECHR (prohibition of inhuman and degrading treatment) provided there is a review mechanism. In England and Wales, the Lord Chief Justice can review a whole life order after 25 years in exceptional circumstances, such as a significant change in the prisoner’s condition.
When setting the minimum term, the judge starts from the appropriate starting point and then adjusts. Aggravating factors (which increase the term) include: a history of violence, use of a weapon, planning, vulnerability of the victim, and abuse of a position of trust. Mitigating factors (which reduce the term) include: lack of premeditation, mental disorder, youth, provocation (which may reduce murder to manslaughter), and assistance to the prosecution.
One of the most significant problems with the current law is that there is no partial defence of excessive force in self-defence. If the defendant used force that was reasonable in self-defence, the killing is lawful. If the force was excessive, the defendant is guilty of murder — there is no halfway house. This means that a person who acts in genuine but excessive self-defence is treated the same as a cold-blooded killer. The mandatory life sentence applies regardless of the circumstances that led to the killing.
A person who kills a terminally ill loved one at their request, out of compassion, is guilty of murder and will receive a mandatory life sentence. The law does not recognise a defence of mercy killing. In practice, judges often set a very low minimum term in such cases, but the conviction for murder remains. Many people consider this unjust because the defendant acted from love and compassion, not from malice.
The mens rea for murder is widely criticised because it does not require an intention to kill. A defendant who intended to cause GBH but did not intend death is guilty of murder just as much as someone who deliberately killed. The Law Commission has argued that the current law fails to distinguish between different degrees of culpability, leading to unjust outcomes. Someone who acted recklessly but caused death can face the same charge as a calculated killer.
The Law Commission has made several proposals to reform the law of murder. In its 2006 report "Murder, Manslaughter and Infanticide," it recommended replacing the mandatory life sentence with a discretionary sentence and creating a two-tier structure for murder. Under this proposal, "first degree murder" would require an intention to kill, while "second degree murder" would cover killings where the defendant intended to cause GBH or was reckless. First degree murder would carry a life sentence; second degree murder would have a maximum of life but allow judicial discretion.
The concept of degrees of murder would allow the law to distinguish between different levels of culpability. First degree murder (intent to kill) would reflect the most serious cases and carry a life sentence. Second degree murder (intent to cause GBH, or killing in the course of another felony) would still be a very serious offence but would allow the judge to choose an appropriate sentence. This approach is used in many other jurisdictions, including the United States, and has been widely supported by legal academics and practitioners.
Despite repeated Law Commission reports and widespread agreement that the law needs reform, Parliament has not acted. There are several possible reasons: the political sensitivity of appearing "soft on murder," the complexity of reforming such a fundamental area of law, and the difficulty of finding parliamentary time for major criminal law reform. The mandatory life sentence also has strong public support, making it politically difficult to change. For now, the common law definition and the mandatory life sentence remain in force.