• Top 1% of Defence Law Firms

  • Defended over 50,000 Cases

  • 5 star google reviews

  • 40 Years of Criminal Law Expertise

Criminal Defences

A Guide to Manslaughter Defences

Learn more about defences that can be used for the offence of Manslaughter.

 If you have been charged with manslaughter, you are probably feeling worried, confused, and unsure about your options. You may be questioning the difference between manslaughter and murder and wondering what the prosecution will need to prove in order to convict you. To help, this article gives an overview of the offence of manslaughter in English law. It summarises the types of evidence that the prosecution is likely to draw upon and examines the maximum sentence that you could face. Importantly, it also outlines manslaughter defences that you may be able to rely upon to reduce or eliminate a possible sentence altogether.

 An overview of the offence of manslaughter

 Like murder, manslaughter is an offence that relates to the unlawful killing of a person. The key difference between the two offences is the intention of the defendant at the time that the killing took place. To be convicted of murder, you must intend to kill or seriously harm the person. You will be charged with manslaughter, however, if your actions have resulted in a person’s death and there was some wrongdoing on your part, yet you did not intend to take their life or to seriously harm them.

There are several different types of manslaughter in English law. Your charge sheet will indicate the particular offence you are accused of committing, but here is a quick overview:

Involuntary manslaughter

Involuntary manslaughter includes both ‘gross negligence manslaughter’ and ‘manslaughter arising from an unlawful and dangerous act’. These offences sound complicated, but some examples help outline when each offence might occur.

Gross negligence manslaughter

This is where the defendant fails grossly (very seriously) in their duty of care towards the victim, resulting in their death. To be convicted of gross negligence manslaughter, the victim’s death must have been a reasonably foreseeable consequence of the defendant’s action. For example, a doctor may be convicted of gross negligence manslaughter if they prescribe a patient a drug to which their medical notes show that they are allergic, resulting in their death. Gross negligence manslaughter also includes more common scenarios, like killing someone by dangerous driving.

Manslaughter arising from an unlawful and dangerous act

You can also be convicted of manslaughter if you commit an act that is both unlawful and dangerous, which results in a person’s death. An example might be people messing around on motorway bridges, throwing rocks at oncoming cars. If a rock hits a windscreen and causes a car to crash, killing the driver, those throwing the rocks could be convicted of manslaughter even though they didn’t necessarily intend that someone should die. This type of manslaughter also includes a death arising from a bar brawl, where the defendant did not intend the victim serious harm. When the court considers the dangerousness of a defendant’s behaviour, it will apply the objective test of whether all sober and reasonable people would recognise the act to be dangerous. In doing so, the court essentially ignores what the defendant thought was reasonable.

Corporate manslaughter: This is where the actions or omission of a company or other organisation result in the loss of life. The failings must be by a senior level of management. For example, a firm may be charged with corporate manslaughter if a builder is killed on a construction site due the failure to implement appropriate health and safety procedures.

Manslaughter through diminished responsibility or loss of control: In our article detailing defences to murder, we explained that two partial defences are diminished responsibility (lack of mental intention to kill or seriously harm due to mental health issues) and loss of control (where the defendant’s actions are influenced by events of a very grave or serious nature which cause them to lose control of their actions). If a defendant successfully pleads either of these defences to a charge of murder, they may instead be convicted of manslaughter.

What kind of evidence is used in manslaughter cases?

If the act took place in public, the prosecution is likely to rely on any available CCTV footage. Witness testimonies of anyone who witnessed events will undoubtedly be crucial to both the prosecution and the defence.

If the death occurred at work, employment records such as training and disciplinary records are likely to be significant. Expert witnesses may be used by the prosecution in an attempt to prove that the defendant’s behaviour was grossly negligent, or dangerous. For example, if the death occurred at a building site, construction experts in the health and safety sector may be called to show how the defendant’s behaviour deviated from accepted practice.

The defence may also call experts to suggest that the defendant’ behaviour fell within the norm, and the death occurred for a different reason, such as the negligent actions of the victim.

What is the maximum sentence for manslaughter?

In 2018, the UK government published guidelines that must be followed by the courts when sentencing for manslaughter. These guidelines apply to defendants aged 18 and older. The maximum sentence for manslaughter is life imprisonment. However, there is a huge variation in the possible sentences, depending on the culpability (blameworthiness) of the defendant’s conduct and other factors.

Gross negligence manslaughter: If convicted of this offence, you would face imprisonment for between 1 and 18 years. You are likely to face a longer sentence if you were aware of the victim’s suffering or risk of death and you persisted with your behaviour, or if your behaviour occurred in the context of other criminality (for example, where robbing a shop).

Unlawful act manslaughter: The range of custodial sentences is between 1 to 24 years. Factors that suggest higher culpability include an intention to seriously harm the victim and committing the offence whilst seeking to escape arrest. Other aggravating factors include previous criminal convictions, playing a leading role in a group, or abusing a position of trust. If this offence was committed against an emergency worker, the sentence is life imprisonment, unless the defence can convince the jury of exceptional circumstances.

Detailed manslaughter sentencing guidelines can be found here.

What are the applicable manslaughter defences?

Defences to the charge of manslaughter vary widely depending on the nature of the case. For gross negligence manslaughter, you may be able to mount a defence on the basis that your actions were not bad enough to be considered grossly negligent. The courts have interpreted this to mean an act must be truly, exceptionally bad. For example, a doctor may argue that whilst the patient did not receive optimal care, and subsequently died, the level of treatment that they received was not so bad that it deserves criminal punishment.

In relation to unlawful act manslaughter, the defence may be able to cast doubt in the jury’s mind that the defendant’s actions would be considered to be dangerous by the sober and reasonable person.

If your company or organisation has been accused of corporate manslaughter, perhaps the offending behaviour was conducted by a junior official, without the knowledge of senior management. You may be able to mount a successful defence on this basis. Corporate manslaughter cases can be especially complex, so always consult a qualified solicitor for help.

General defences

In some circumstances, you may be able to rely upon what is called a ‘general defence’ to manslaughter. General defences relate to the person accused rather than the crime itself. General defences include:

Self-defence: The law says that if you are attacked, you may use the force that is reasonably necessary to defend yourself. You may also use reasonable force to defend another person, property, to prevent crime, or to conduct a lawful arrest. For example, if you were attacked, and you retaliated to protect yourself or someone else, you may be able to rely on this defence.

 Duress: This is where you were forced by a person or a set of circumstances to commit an offence. The court will consider whether you reasonably feared death or serious injury if you did not commit the act, and whether a reasonable person in your situation would have shared those fears and responded in the same way.

Automatism: If you were not aware of your actions when committing the offence, in some rare circumstances, you may be able to rely upon the defence of automatism. Generally, if you were under the voluntary influence of alcohol or illicit drugs you will not be able to rely on this defence.

Insanity: If the court finds that due to mental illness, you lacked the ability to reason such that you did not know that the act that you were doing was against the law, you may be acquitted on the grounds of insanity.

Intoxication: The courts are reluctant to accept voluntary intoxication e.g. choosing to consume drugs and alcohol as an excuse for criminal behaviour. However, you may be able to rely on this defence in some circumstances (for example, if you were involuntarily drugged at the time of the events or if you were affected by the prescription medication).

Mistake: This defence could apply if you were mistaken as to certain factual circumstances and would not have committed the offence is you had known otherwise. You cannot rely on your mistaken understanding of the law as a defence.

What will a successful defence achieve?

A successful defence may lead to you being acquitted or convicted of a lesser charge. This could mean you escape punishment altogether, or that you get a shorter sentence. Defences to manslaughter are highly fact dependent, so it is always advisable to seek advice on your case from a criminal defence solicitor.

Where can I get help with manslaughter offences?

If you, someone you care about, or indeed your company has been accused of manslaughter, Stuart Miller Solicitors is here to help. With tens of years of experience defending manslaughter cases, we will provide you with robust advice on your case and realistic guidance on the options that are available to you. Contact us for a no obligation consultation today.

(This page was last updated on November 22, 2023.)


Call 24 hours a day, 7 days a week.