dimished responsibility

• X may be able to avoid liability for murder and instead be liable for the offence of voluntary manslaughter. Voluntary manslaughter arises where both the actus reus and the mens rea is met but a special partial defence can be successfully pleaded. Here X may plead the defence of diminished responsibility.
• This defence is outlined in Section 52 of the Coroners and Justice Act 2009.
• Firstly, under S. 52(1), the D must be suffering from an abnormality of mental functioning.
• The case of Byrne shows that mental functioning will be regarded as abnormal where the D's mental functioning was so different from that of an ordinary human being that a reasonable person would consider it abnormal.
• Secondly, under S. 52(1)(a), the abnormality of mental functioning must arise from a recognised medical condition.
• Recognised medical conditions:

  • Temporary conditions as outlined in Reynolds (post-natal depression)
  • Battered spouse syndrome as shown in Ahluwalia
  • Pre-menstrual tension as outlined in Smith
  • Depression (and other mental disorders like schizophrenia) as outline in Gittens or Deitschmann.
• Recognised medical conditions:

  • Intoxication cannot support a defence of diminished responsibility (Di Duca)
  • However alcohol dependency syndrome can be RMC as outlined in wood and Stewart
  • Alcohol related brain damage from prolonged abuse of alcohol and drugs can qualify as a recognised medical condition but this needs to be proven (Wood)
  • Any physical condition, which affects mental functioning (such as epilepsy- Campbell)
  • medical evidence will be needed to support this (brennan)but the defendant does not have been diagnosed t the time of his killing.
• Thirdly, under s.52(1)(b), the abnormality of mental functioning must substantially impair the D's ability to do one or more of the things mentioned under subsection 1A:

  1. Understand the nature of his conduct - they don't understand what they are doing
  2. form a rational judgement - lack of thinking
  3. exercise self control - they lack control
• • In the recent case of Golds, the court said in order for it be substantial, it must be something that really made a great difference.
• Finally under s.52(1)(c), the abnormality of mental functioning must provide an explanation for the killing. This means it must be shown that the D's act or omission which lead to the killing was because he has a mental impairment.
• S.52(1B) provides that the abnormality of mental functioning can be a significant contributory factor and so there can be other factors too this is illustrated in cases like Deitschman.