Over the last five decades, our manslaughter solicitors have successfully acted in dozens of serious cases of accidental death or cases resulting in manslaughter by diminished responsibility, on some occasions these fatal cases involving more than one death.

We have included two basic case studies of cases we have recently defended, and a brief guide to the law of manslaughter and how it applies in criminal cases below. For offences alleged against professionals or companies, see our page on Gross Negligence and Corporate Manslaughter.

Our specialist manslaughter solicitors' case studies

Any lawyer can claim to have expertise in manslaughter cases. Mary Monson defended her first homicide case in 1982, and we have acted in dozens of manslaughter and murder cases since then. We have included here two case studies to give an idea of how we work.

Case Study 1 - Domestic mercy killing

Our client was charged with the murder of his elderly mother who was close to death from cancer. The defendant maintained that he had smothered her as an act of mercy as she was in great pain.

After considering psychological reports commissioned by our team the prosecution accepted a plea of guilty to manslaughter on the grounds of diminished responsibility. Our client has since been released.

Case Study 2 - Manslaughter in a fight

Our client had been convicted of murder in a first trial having been represented by a different firm of solicitors. The prosecution case was that he and a friend had attacked the victim with a knife.

We successfully appealed to the Court of Appeal and a retrial was ordered. We persuaded the jury that our client, unlike the codefendant, had not intended to kill or cause serious injury, even though he had been involved in the fight. The jury preferred a verdict of manslaughter to the original murder conviction, and the client was released soon after.

What is Manslaughter?

Manslaughter is a word describing the killing of another person but without the full blame of murder.

One category of manslaughter is where the person intended the victim to be killed or seriously harmed, but the law allows a possible verdict of manslaughter. These cases always start out as murder cases, but can be reduced to manslaughter on the basis of diminished responsibility, loss of control, or a suicide pact.

These cases are called voluntary manslaughter, because the defendant still had an intention to kill.

Here, the prosecution would charge murder and it is for the defence to raise the defence of diminished responsibility, loss of control or suicide pact.

A second category of manslaughter cases is where the person did not intend for anyone to die or be seriously harmed, but is still in some way criminally to blame. This category of cases is called involuntary manslaughter.


What is diminished responsibility?

Manslaughter by diminished responsibility is not really an offence but is more of a defence to a charge of murder. The law says that someone who kills another person should not be convicted of murder if he or she was suffering from an ‘abnormality of mental functioning' also simply called a mental abnormality. This phrase means something wrong with the way that person's mind was working at that time. It must be as a result of a recognised medical condition to count as a mental abnormality. This could include a serious mental condition such as schizophrenia, but could include less serious mental health complaints such as attention deficit hyperactivity disorder (ADHD), or even depression.

For a verdict of manslaughter, the abnormality also has to have resulted in the accused person having substantial difficulty with doing one of the following three things:

  1. understanding what he or she was doing

  2. having difficulty thinking rationally

  3. having difficulty controlling him or herself.

If (and only if) one or more of these difficulties provide an explanation for the accused person's involvement in the murder, then the murder charge may be reduced to manslaughter by diminished responsibility. ‘Providing an explanation for the accused person's involvement' here means that the difficulty significantly contributed to his or her behaviour.

Sunstnaitallly has been considered in the case of Golds recently. Also a court of appeal case of Lindo - diminished responsibility is not available to drug induced psychosis - equate it with alcohol.

Manslaughter as a result of Loss of Control

Manslaughter by loss of control is also not really an offence. A person cannot be charged with manslaughter by loss of control. It is actually a defence to murder which usually results in a heavily reduced sentence.

Where somebody has killed another person and intended to do so, the person who has killed may be able to claim the defence of manslaughter by loss of control if all of the following conditions are met:

  • The killing has to be as a result of a loss of self control,

  • The loss of self control has to be caused by either;

  1. The fear of serious violence, or;

  2. something serious which was said or done at the time and which gave the impression of being ‘wronged', or;

  3. a combination of the the two above causes

There are some other conditions for a defendant to rely on the defence of manslaughter by loss of control.

Firstly, the jury must believe that it is possible that an average person in the same circumstances, and of the same sex and age might have acted in the same or a similar way.

Revenge, because it is a considered rather than a spontaneous thing, is not a motive which can be a cause of the loss of control for manslaughter to be a defence to murder.

Infidelity on its own is also excluded as a reason for a loss of control to be valid, but the circumstances in which the infidelity is discovered, depending on the facts, could be considered.

The loss of control does not have to be sudden. This covers situations in which somebody who is regularly beaten may one day ‘snap' and kill the abuser. In the past, this has been called ‘slow burn provocation'.

In a criminal case, it is up to the defence to raise the possibility of loss of control. The defendant is then not guilty of murder and is instead guilty of manslaughter unless the prosecution can prove that loss of control does not apply.

Failed Suicide Pact

In a situation where two people had agreed to commit suicide together, one of them killing the second or helping him or her to kill himself, this is not murder, but manslaughter. Of course this would only be the case if the first person didn't follow through with his or her own suicide. It is also important to know that is a person wants to claim the defence of manslaughter as a result of suicide pact, that person has to prove that there was a suicide pact. For a jury to believe that this was genuinely a suicide pact, they will probably want some explanation as to how it was that the defendant survived.

Involuntary Manslaughter

Involuntary manslaughter is when somebody has killed another person but did not intend for that person to die or be seriously injured.

It broadly falls into two categories. The first is manslaughter by a dangerous and unlawful act (sometimes called MUDA). The second is manslaughter by gross negligence.

Manslaughter by Unlawful and Dangerous Act (MUDA)

The most common type of manslaughter by an unlawful and dangerous act is where a person assaults another person without intending to cause serious damage or death, but the victim dies anyway. This could occur, for example, in a fist fight, where there was no weapon used. The intention may be to assault the victim, but not to seriously assault or kill the victim. The intention for murder is not there, so the death is manslaughter.

‘One punch' manslaughter cases

One example of MUDA is where a person punches someone on one occasion, and the victim suffers an injury as a result causing death. These cases are sometimes described as ‘one punch manslaughter'. In these cases, the death is not usually a consequence to the assault that could have been easily foreseen. The death in these cases is usually caused by a head injury or heart attack, often as a result of falling awkwardly or landing on a hard surface such as a roadside kerb. In some cases, of course, the punch itself can cause the death. Perhaps the most common type of injury which occurs in this case is a subarachnoid haemorrhage, which happens when an artery near the brain is damaged. It can occur from a single, and as a result of the head moving suddenly.

Unlawful and dangerous act manslaughter can also take place when somebody causes the death of another person while carrying out another offence. An example of this might be where a person carries out an arson attack without intending for anyone to be seriously hurt or killed, but somebody still dies as a result. The unlawful and dangerous act is the arson, and the fact that death has followed, even without it being intended, means that the arsonist could be guilty of manslaughter. In these cases, what the arsonist knew and what steps he or she took to know about whether somebody was in the building is very important. If he or she knew somebody was inside, the prosecution would probably bring a case for murder. If he or she made no checks or appeared not to consider whether somebody was inside, then there may be a higher possibility that this is manslaughter.

Gross Negligence Manslaughter

In circumstances where a person had a duty to be careful in his or her treatment of another person and the other person died as a result of gross negligence (gross negligence means behaving very carelessly indeed), then the first person may be guilty of gross negligence manslaughter. This could, for example, be in a situation where a doctor or other professional carries out his or her duties so poorly that death follows.

If the death is caused by the collective mismanagement of a company or other organisation in the way it looks after its customers or other people it is responsible for, the company could face a charge of Corporate Manslaughter. Read  more detailed information on Gross Negligence Manslaughter and Corporate Manslaughter.


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