Regina v. Dietschmann (Appellant) (On Appeal from the Court of Appeal (Criminal Division)).

Under section 2(1) of the Homicide Act 1957, a defendant who had voluntarily consumed alcohol need not prove that, if sober, he would still have killed. A qualifying abnormality of mind need not be the sole cause of the fatal conduct.

The jury must disregard alcohol as a cause of the qualifying abnormality and of any impairment arising from it. The jury must nevertheless consider whether, despite the alcohol and its disinhibiting effect, the abnormality substantially impaired the defendant’s mental responsibility for the fatal acts. If the defendant proves that issue on the balance of probabilities, the proper verdict is manslaughter rather than murder.

The appellant killed the victim during a prolonged assault after consuming substantial quantities of alcohol. At the time, he was also suffering from an adjustment disorder arising from bereavement. The psychiatrists agreed that this constituted an abnormality of mind, but disagreed about its effect on his mental responsibility and the significance of the alcohol.

At Liverpool Crown Court, the jury was directed that diminished responsibility could succeed only if the appellant proved both that, without drink, he would still have killed and that he would then have been under diminished responsibility. The jury convicted him of murder. The Court of Appeal dismissed his appeal in [2001] EWCA Crim 2052.

The issue before the House was whether section 2(1) of the Homicide Act 1957 required the defendant to prove that the killing would have occurred without alcohol and, if not, how the jury should be directed where intoxication and a qualifying abnormality coexisted.

1. Disposition. Lord Hutton delivered the leading speech. Lord Nicholls, Lord Lloyd, Lord Hobhouse and Lord Rodger agreed with his reasons and proposed order. The House unanimously allowed the appeal and remitted the case to the Court of Appeal to decide whether to quash the murder conviction and order a new trial, or substitute manslaughter and impose an appropriate sentence.

2. Construction of section 2. Per Lord Hutton, section 2(1) of the Homicide Act 1957 does not require a qualifying abnormality of mind to be the sole cause of the killing. Even where the defendant would not have killed without drinking, alcohol’s causal contribution does not necessarily prevent the abnormality from substantially impairing mental responsibility. The first part of the certified question was therefore answered in the negative.

3. Proper jury direction. Per Lord Hutton, the jury must first determine whether the defence has proved a qualifying mental abnormality. Alcohol cannot be treated as contributing to that abnormality or to impairment arising from it. The jury may, however, recognise that both alcohol and the abnormality affected the defendant. The decisive question is whether, despite the drink, the defendant has proved on the balance of probabilities that the abnormality substantially impaired his mental responsibility for the fatal acts. If so, the verdict may be manslaughter; otherwise diminished responsibility is unavailable.

4. Authorities. Per Lord Hutton, Fenton and Gittens correctly stated the law. Gittens established that the jury must assess the qualifying abnormality after leaving alcohol out of account as a source of that abnormality, without asking which factor was the principal cause of the conduct. Turnbull (Launcelot) did not establish a contrary principle and its problematic direction should not be followed.

   The adoption in Atkinson and Egan of the two hypothetical questions proposed in the earlier academic commentary was erroneous and irreconcilable with Gittens. The separate direction approved in Egan—asking whether the abnormality substantially reduced responsibility, drink or no drink—was correct.

5. Policy. Per Lord Hutton, this construction does not make intoxication a defence to murder. It gives effect to Parliament’s distinct treatment of a person whose qualifying mental abnormality substantially impaired responsibility, even though alcohol also contributed to the killing.

1. House of Lords: The appeal was allowed unanimously. The case was remitted to the Court of Appeal to determine whether to quash the murder conviction and order a new trial, or substitute manslaughter and pass an appropriate sentence.

2. Court of Appeal (Criminal Division): In [2001] EWCA Crim 2052, the court dismissed the appeal against conviction and upheld the trial judge’s use of the two hypothetical questions concerning what would have occurred without drink.

3. Liverpool Crown Court: Maurice Kay J directed the jury that diminished responsibility required proof that, without drink, the appellant would still have killed and would have been under diminished responsibility. The jury convicted the appellant of murder and he was sentenced to life imprisonment.