Regina v Dietschmann (Appellant)

The House of Lords considered the correct jury direction where a defendant charged with murder relied on diminished responsibility under section 2 of the Homicide Act 1957 and had been drinking before the killing. The court held that the prosecution of diminished responsibility does not require the defendant to prove that, but for the drink, he would have killed. Rather, the jury must be directed to disregard alcohol insofar as it is relied on as causing the abnormality of mind described in section 2, but may take into account that drink had a disinhibiting effect. The central question for the jury is whether the abnormality of mind (as defined in section 2) nevertheless substantially impaired the defendant's mental responsibility for the killing despite the presence of intoxication.

The House approved the approach in R v Fenton and R v Gittens and disapproved aspects of the approach adopted in R v Atkinson and R v Egan to the extent that they required proof that the killing would have occurred sober. The matter was remitted to the Court of Appeal to determine whether the murder conviction should be quashed and substituted with manslaughter or whether a new trial should be ordered.

Background and procedural posture:

• The appellant, Anthony Dietschmann, was convicted of murder at Liverpool Crown Court on 7 April 2000 after a jury rejected his defence of diminished responsibility; he was sentenced to life imprisonment. His appeal to the Court of Appeal was dismissed on 5 October 2001 ([2001] EWCA Crim 2052). He then appealed to the House of Lords.

Nature of the appeal: The appellant sought to challenge the jury direction given at trial on diminished responsibility in circumstances where the defendant had consumed alcohol before the killing, asking whether the defence must prove that, absent the drink, he would both have killed and have been under diminished responsibility.

Facts and evidence: The appellant had been grieving the death of his aunt and, shortly after his release from custody, drank heavily; he attacked and killed Nicholas Davies after an altercation. Medical evidence agreed he suffered an adjustment disorder (a depressed grief reaction). The psychiatrists disagreed as to alcohol dependence and whether a transient psychotic state existed; they also differed on whether the abnormality substantially impaired responsibility.

Issues for determination:

• (i) Whether a defendant must show that, if he had not taken drink, he would have (a) killed as he did and (b) have been under diminished responsibility.
• (ii) If not, what direction should be given to a jury about self-induced intoxication present with an abnormality of mind under section 2(1) of the Homicide Act 1957.

Court's reasoning and conclusion: The House concluded the first question should be answered in the negative. The court explained that section 2(1) focuses on whether an abnormality of mind substantially impaired mental responsibility and does not require that the abnormality be the sole cause of the killing. The jury should be told to exclude alcohol when considering whether an abnormality of mind (within section 2) existed and materially impaired responsibility; however they may still consider that both the abnormality and drinking played a part and then decide whether the abnormality, despite the drink, substantially impaired responsibility. The House relied on and approved the reasoning in R v Fenton and R v Gittens and rejected an interpretation of later Court of Appeal authorities that imposed the hypothetical sober-where-would-he-have-killed requirement. The matter was remitted to the Court of Appeal to determine whether to quash and substitute a manslaughter verdict or order a new trial.

Appeal allowed. The House held that a defendant relying on diminished responsibility need not prove that, if he had not taken drink, he would have killed or would have been under diminished responsibility. The jury should be directed to disregard alcohol as causing the abnormality within section 2, but may consider drink's disinhibiting effect and must decide whether the abnormality nonetheless substantially impaired mental responsibility. The case was remitted to the Court of Appeal to decide the appropriate disposal.

Conviction after trial at Liverpool Crown Court (verdict 7 April 2000). Appeal to the Court of Appeal (Criminal Division) dismissed on 5 October 2001 [2001] EWCA Crim 2052. Appeal to the House of Lords allowed [2003] UKHL 10 and remitted to the Court of Appeal.