What Is Manslaughter? The Line Between Murder and an Unlawful Killing
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Two people die in two pubs on the same night, each from a single punch. One puncher meant to kill and the other meant a brawl, and the law of England treats them differently in name, in sentence and in what the jury must decide, though the victims are equally dead. Homicide, the killing of one person by another, is divided by the state of the killer's mind, and manslaughter is the name for the killings that fall short of murder's intent or that the law excuses in part, which makes it the crime whose boundaries are most argued over in the courts.
The mental element
Murder in English law is killing with intent to kill or to cause really serious harm, and nothing more; motive, planning and cruelty are matters for sentence, not for the definition. Manslaughter is every other unlawful killing, and the difference is entirely in the mind of the defendant at the moment of the act, which is why homicide trials are so often about what a person was thinking rather than what they did. In the United States the grades are finer, first-degree murder for planned killing, second-degree for intentional but unplanned, voluntary and involuntary manslaughter below, and the states differ; Scotland has murder and culpable homicide; but the principle in every common-law system is that the same death is a different crime according to what was intended.
Two kinds
English manslaughter comes in two families:
- •Voluntary manslaughter: the defendant had the intent for murder, but a partial defence reduces the crime; loss of control, formerly provocation, where the killing followed a qualifying trigger such as fear of serious violence; diminished responsibility, where a recognised mental condition substantially impaired the defendant's judgement; and the survivor of a suicide pact
- •Involuntary manslaughter: there was no intent to kill or seriously injure, but the killing was still criminal; unlawful act manslaughter, where the death followed a crime that a reasonable person would see as risking some harm, the one-punch case; and gross negligence manslaughter, where a duty of care was breached so badly that the breach was criminal, the surgeon, the employer, the landlord with the faulty boiler
The sentence
The distinction matters most at sentence. Murder carries a mandatory life sentence in England, with a minimum term set by the judge from starting points of 15, 25 or 30 years and whole life for the worst; the judge has no discretion to pass anything else, which is why juries are sometimes reluctant to convict of it and why the partial defences exist. Manslaughter carries a maximum of life and a minimum of nothing, and sentences run from a suspended term for a gross negligence case of momentary inattention to twenty years or more for a killing that was nearly murder. In the United States the death penalty, where it exists, attaches only to the highest grade of murder, and the plea bargain from murder to manslaughter is the ordinary mechanism by which most American homicide cases end.
The hard cases
The line is tested in the same situations every generation. The abused partner who kills a sleeping abuser had no defence of provocation, since the old law required a sudden loss of temper, and the reform of 2009 that replaced provocation with loss of control was written for that case, with fear of serious violence as a trigger and no requirement of suddenness; sexual infidelity was expressly excluded as a trigger, ending the defence that had reduced killings of unfaithful wives to manslaughter for two centuries. The one-punch killing is the other, since the puncher intended a punch and got a death, and the courts hold that the risk of some harm is enough, which critics say punishes bad luck; a campaign in Australia produced a specific one-punch offence with a mandatory minimum. Corporate manslaughter, created in England in 2007, lets a company be convicted where its management failures caused a death, which was previously nearly impossible because no single director could be shown to have had the guilty mind.
Why it matters
The categories exist because a legal system that punished all killings alike would be unjust in one direction and one that let intention excuse everything would be unjust in the other. Manslaughter is the space between, in which the law says a death was wrong and the wrong was less than the worst, and the arguments over its edges, what counts as loss of control, how gross negligence must be, whether a punch is a risk of harm, are the arguments about how much of a person's state of mind a court can be expected to reconstruct and how much weight to give it. The two people in the two pubs will be judged by what a jury believes they meant, and that is both the best a legal system can do and a permanent source of dispute.
The takeaway
Manslaughter is unlawful killing without the intent to kill or cause serious harm that defines murder, or with that intent reduced by a partial defence of loss of control, diminished responsibility or a suicide pact; involuntary manslaughter covers deaths from an unlawful act that risked some harm and from gross negligence in a duty of care. Murder carries a mandatory life sentence and manslaughter a discretionary one, and the line between them turns on the defendant's state of mind, which is why the hard cases are the abused partner, the one punch and the negligent company.