Bunch, R. v

A defendant seeking to rely on diminished responsibility must adduce evidence capable of proving every requirement in section 2 of the Homicide Act 1957, on the balance of probabilities. Medical evidence is not expressly mandated by the section, but will ordinarily be a practical necessity, particularly to establish a recognised medical condition and an abnormality of mental functioning.

Voluntary intoxication, however heavy or frequent, cannot found the partial defence. Alcohol dependency may be capable of doing so, but only where there is evidence that it produced the requisite abnormality, substantial impairment and explanatory causal connection to the killing.

Martin Bunch was convicted at Chelmsford Crown Court of the murder of Jeanette Goodwin and sentenced to life imprisonment with a minimum term of 27 years, less time spent on remand. The prosecution case was that he stabbed the deceased after a terminated affair and prior threatening behaviour.

At trial, Bunch denied involvement. Alternatively, he relied on intoxication to contend that he lacked the intent for murder. He called no medical evidence of alcohol dependency. The trial judge refused to leave diminished responsibility to the jury. A single judge refused leave to appeal against conviction, and Bunch renewed that application before the full court.

The central issue was whether the evidence was sufficient to require the jury to consider diminished responsibility based on alleged alcohol dependency.

1. The renewed application for leave to appeal against conviction was dismissed. The trial judge was correct not to leave diminished responsibility to the jury.
2. Under section 2 of the Homicide Act 1957, the defence had to prove on the balance of probabilities that Bunch suffered from an abnormality of mental functioning arising from a recognised medical condition, that it substantially impaired a specified capacity, and that it caused or significantly contributed to the killing. There was no evidence capable of establishing those requirements.
3. The amendment made by the Coroners and Justice Act 2009 did not diminish the authority of Byrne [1960] 2 QB 396 and Dix 74 Cr App R 306. Although section 2 does not expressly require medical evidence, such evidence remains a practical necessity if the defence is to succeed, given that the burden lies on the defendant.
4. The evidence of alcohol dependency was weak and unsupported by expert evidence. Even if a jury could have found that Bunch was alcohol-dependent, it had no evidential basis to find an abnormality of mental functioning, substantial impairment, or the necessary explanatory connection. Voluntary intoxication could not found diminished responsibility: Dowds [2012] 1 Cr App R 34. Alcohol dependency may be capable of doing so, but the evidence did not justify leaving that partial defence to the jury.

• Court of Appeal (Criminal Division): The full court dismissed the renewed application for leave to appeal against conviction.
• Court of Appeal (Criminal Division): A single judge had refused leave to appeal against conviction.
• Crown Court at Chelmsford: On 14 August 2012, Bunch was convicted of murder and sentenced to life imprisonment with a minimum term of 27 years, less time spent on remand.