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Prosecuting Homicide

Murder and manslaughter are two of the offences that constitute homicide.

Manslaughter can be committed in one of three ways:

  1. killing with the intent for murder but where there is provocation, diminished responsibility or a suicide pact.
  2. conduct that was grossly negligent given the risk of death, and resulted in death.
  3. conduct, taking the form of an unlawful act involving a danger of some harm, that caused death.

With some exceptions, the crime of murder is committed, where a person:

  • of sound mind and discretion (i.e. sane):
  • unlawfully kills (i.e. not self-defence or other justified killing)
  • any reasonable creature (human being)
  • in being (born alive and breathing through its own lungs)
  • under the Queen's Peace
  • with intent to kill or cause grievous bodily harm.

There are other specific homicide offences, for example, infanticide, causing death by dangerous driving, and corporate manslaughter.

Find out more about prosecuting homicide

CPS no longer seeking special verdict in case of Brian Thomas


Following expert evidence from a psychiatrist in the case of Brian Thomas, where a jury was being asked to consider the unusual issue of insane automatism - a sleep disorder known as "night terror" - the Crown Prosecution Service has decided to pursue this case no further.

Iwan Jenkins, Chief Crown Prosecutor for CPS Dyfed Powys, said: "This has been a unique case with a unique set of circumstances.

"We have a duty to keep cases under continuous review, and following expert evidence from a psychiatrist it was suggested no useful purpose would be served by Mr Thomas being detained and treated in a psychiatric hospital, which would be the consequence of a special verdict in this case.

"Once it was raised, the CPS had a duty to review the case and decided that, guided as we must be and have been throughout this case by the views of the experts, the public interest would no longer be served by continuing to seek a special verdict of not guilty by reason of insanity.

"The consequences of such a finding would have meant Mr Thomas' detention in a psychiatric hospital, but it is now clear that the psychiatrists feel that that would serve no useful purpose and the risk of reoccurrence is very, very small. We therefore have offered no further evidence and asked the jury to return a simple verdict of not guilty."

There has never been any dispute that Mr Thomas caused his wife's death, said Mr Jenkins, but the prosecution accepted that he should be found not guilty of murder or manslaughter, based on the evidence of a number of experts in the field of sleep-related disorders.

Further expert evidence led to a range of opinions on whether Mr Thomas presented any ongoing risk, and therefore whether he required further medical intervention.

Mr Jenkins said: "For that further treatment to be made a requirement, a special verdict of 'not guilty by reason of insanity' would be required. The law dictates that this is a verdict that cannot be determined by anyone other than a jury which is why the case had to go to court.

"The death of Christine Thomas was thoroughly investigated by Dyfed Powys Police. Investigations continued after Mr Thomas was charged and involved the instruction of experts in several fields.

"I must emphasise that the circumstances of this case are almost unique in the UK and there have been fewer than 50 instances recorded worldwide. It is only because of highly sophisticated tests carried out by sleep experts that Mr. Thomas' condition could be confirmed.

"Our thoughts remain with the family of Brian and Christine Thomas who have remained dignified throughout this difficult time."


  1. Media enquiries by email: CPS Press Office or by phone: 020 7710 8127, Out of hours pager: 07699 781926. Wales media enquiries on 02920 803950
  2. The difference between diminished responsibility and insanity: Diminished responsibility is a partial defence to murder the defendant is convicted of manslaughter if diminished responsibility is proven. A defence of insanity is a total defence to murder and the defendant is acquitted. However, this is a special verdict and, in a murder case with this verdict, the court must impose a hospital order with no restraint on time.
  3. The Crown Prosecution Service is the independent authority responsible for prosecuting criminal cases investigated by the police in England and Wales. It is responsible for:
    • Advising the police and reviewing the evidence on cases for possible prosecution
    • Deciding the charge where the decision is to prosecute
    • Preparing cases for court
    • Presenting cases at court
  4. The CPS consists of 42 Areas in total, each headed by a Chief Crown Prosecutor (CCP). These are organised into 14 Groups, plus CPS London, each overseen by Group Chair, a senior CCP. In addition there are four specialised national divisions: Organised Crime, Special Crime, Counter-Terrorism and the Fraud Prosecution Service. A telephone service, CPS Direct, provides out-of-hours advice and decisions to police officers across England and Wales. The CPS employs around 8,250 people and prosecuted 1,032,598 cases with an overall conviction rate of 86.6% in 2008-2009. Further information can be found on our website. More about the CPS
  5. The CPS, together with ACPO and media representatives, has developed a Protocol for the release of prosecution material to the media. This sets out the type of prosecution material that will normally be released, or considered for release, together with the factors we will take into account when considering requests.

    Publicity and the Criminal Justice System protocol