Diminshed Responsibility

Diminished responsibility” is a partial defence in law, to charges of murder.  It is therefore something for the defence to raise, not for the prosecution to prove; and for it to be established, it must be shown on the balance of probabilities that the defendant “was suffering from such abnormality of mind (whether arising from a condition of arrested or retarded development of mind or any inherent causes or induced by disease or injury) as substantially impaired his mental responsibility for his acts and omissions in doing or being a party to the killing.”

This was covered in section 2 of the Homicide Act 1957, but was updated by the Coroners and Justice Act 2009 and it involves a four-stage assessment, each part of which must be satisfied for a partial defence of DR to succeed –

  1. Whether the defendant was suffering from an abnormality of mental functioning
  2. f so, whether it had arisen from a recognised medical condition
  3. If so, whether it had substantially impaired his ability either to understand the nature of his conduct or to form a rational judgment or to exercise self-control (or any combination)
  4. If so, whether it provided an explanation for his conduct

I have previously written about insanity, which is a separate defence to a criminal charge; and like diminished responsibility, it is a matter for the defendant’s counsel to raise in court.  As with all prosecutions of suspects who suffer from a mental health disorder, a defendant is nonetheless “presumed to be sane, and to possess a sufficient degree of reason to be responsible for his crimes, until the contrary be proved.”  This was laid down by Lord Chief Justice TINDAL in 1843 in the “M’Naughten Rules.”  Diminished responsibility sits somewhere in between the two legal extremes of insanity and sanity: but bringing expert psychiatric opinion into legal frameworks is where it all gets interesting!


Early in 2013, Nicola EDGINGTON was convicted of murder.  It was her second homicide conviction: she had previously been prosecuted for murder in 2006 after killing her mother and had been sentenced to a restricted hospital order after successfully raising “diminished responsibility”.  After her release from hospital in 2009, she lived in Greenwich for a couple of years until in November 2011 she again became unwell and after absconding from a psychiatric unit in Woolwich, killed Sally HODKINS and attempted to kill Kerry CLARK.  When she was prosecuted, she faced charges of murder and attempted murder.

In some cases of homicide where the defendant has obvious mental health problems, the defence will submit to the Crown Prosecution Service the evidence upon which they will seek to rely in arguing “diminished responsibility”.  On some occasions this is sufficient basis for the CPS to be satisfied that the partial defence will succeed and agreement is reached that the defendant plead guilty to manslaughter on these grounds.  This is what happened with Nicola’s first homicide offence, but it is not always the case:

Diminished responsibility is, of course, a legal concept, not a medical one: whilst psychiatrists can offer opinion, it is nevertheless open to the prosecution in any case, to require the defence to put their argument to a court and see whether or not the jury accept it.  Although Nicola EDGINGTON had pleaded guilty to the manslaughter of her mother, the prosecution in 2012 would not accept a similar plea – more information about her mental health was known because she had spent three years in a medium secure unit.  After the defence of diminished responsibility was put forward by her defence counsel, the jury rejected this and she was convicted of murder and attempted murder.  It is important to point out, a criminal appeal is pending – both against conviction and sentence, because it is suggested that as a point of law, the jury were wrong and diminished responsibility should have been the correct outcome: that will be an interesting appeal to watch out for.


The other infamous example of a diminished responsibility argument: when Peter SUTCLIFFE first appeared at the Old Bailey, the prosecution were prepared to accept defence evidence of diminished responsibility and guilty pleas to the various homicide offences committed.

On that occasion, the trial judge insisted on questioning the basis upon which the various examining psychiatrists had reached their conclusions and recommendations.  It transpired that psychiatric reports were written purely on the basis of interviews with SUTCLIFFE about the relevant events.  Perhaps unsurprisingly, he told some lies during examination – lies that could be shown as such by other evidence gathered by the police.  Because of this, Mr Justice BOREHAM put the matters before a jury and SUTCLIFFE’s claim of diminished responsibility was rejected.

Where a defendant is convicted of murder, there can only be one sentence in law: life imprisonment.  So Nicola EDGINGTON, having committed the offence whilst an inpatient in a mental health hospital and with a significant mental heath history, was sent to prison.  Almost certainly, as was the case with Peter SUTCLIFFE, she will be transferred from prison to the hospital system under section 47 of the Mental Health Act, restricted by section 49.  This means she will, in effect, assume the same status as she did when detained after the killing of her mother – that of a “restricted hospital order” patient, under s37/41 of the Mental Health Act.

So what is the point of all this, if those convicted of homicide whilst mentally disordered all end up in the hospital system anyway?

Well, those convicted of murder and given a tariff by the judge upon conviction – this is the minimum period of time that must be served before they can be considered for release.  No such tariff is imposed upon those convicted of manslaughter where diminished responsibility is argued – they are most often sentenced to a restricted hospital order.

Nicola EDGINGTON’s tariff was 37yrs – although I remind you that this is subject to appeal.  If it is felt that it is no longer necessary for her to receive inpatient care as a s47/49 patient, she can be remitted back to prison under s50 MHA to conclude the remaining years of her tariff and her release is controlled by the Parole Board and the criminal justice system.  When she first pleaded guilty to manslaughter and was detained under s37/41, her ongoing detention was governed by the clinical recommendations of her clinical team, overseen by the Mental Health Review Tribunal System.

In other words: this all amounts to a difference between the ability of the criminal justice system to keep control of people who were fully criminally convicted and sentenced for murder, until such time as their sentence is served, even if it does end up being served in a hospital.

Winner of the President’s Medal,
the Royal College of Psychiatrists.

Winner of the Mind Digital Media Award


All opinions expressed are my own – they do not represent the views of any organisation.
(c) Michael Brown, 2013

I try to keep this blog up to date, but inevitably over time, amendments to the law as well as court rulings and other findings from inquests and complaints processes mean it is difficult to ensure all the articles and pages remain current.  Please ensure you check all legal issues in particular and take appropriate professional advice where necessary.

Government legislation website – http://www.legislation.gov.uk

2 thoughts on “Diminshed Responsibility

  1. Tariff is one effect of imposing a prison sentence – absolutely.

    There are other effects. s47/49 is very similar to s37/41, but not identical. The situation with regard a tribunal releasing the person back into the community is different and also management of the case by the ministry of justice (granting leave of absence etc) would be different. Secure health facilities have also been given clear standards regarding preventing the absconding of transferred prisoners (‘never event’).

    All together, I think you could reasonably say that life sentence, followed immediately by transfer to hospital, would give greater protection to the public than a s37/41. It sounds reasonable for the court to have options – people with mental health problems are very diverse.

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