Diminished Responsibility Knowledge Summary

• Partial defence to murder. Contained in s.2 Homicide Act 1957 as amended by s.52 Coroners & Justice Act 2009
• Abnormality of Mental Functioning (AMF)

  D must show that they are suffering from an abnormality of mental functioning, defined in Byrne as 'a state of mind so different from that of the ordinary human being that the reasonable man would term it abnormal'
• Recognised Medical Condition (RMC)

  The cause of the AMF must be a recognised medical condition and can include depression (Reynolds), Battered Wife syndrome (Ahulwalia) and paranoia (Martin). It must be recognised by the medical profession and medical evidence is required. The World Health Organisation's International Classification of Diseases ICD-11 is often used as a source.
• Substantially Impaired: RMC must have substantially impaired D's ability to:

  1. Understand the nature of his conduct (don't know what ehy are doing; Dietschmann)
  2. Form a rational judgement (can't make rational choices about right/wrong; Ahulwalia)
  3. Exercise self-control (can't control their actions; Byrne)

  'Substantially' means more than trivial and less that total(Lloyd) but Golds confirms its everyday meaning should be used and is a matter for the jury.
• Explanation:

  It must be established that there was a causal link and the AMF provides an explanation for D killing V
• Alcohol:

  1. Intoxication alone - Simply taking drink or drugs will not be enough for diminished responsibility (Dowds)
  2. Intoxication & AMF - Jury would ignore the intoxication and decide the D would have killed the V due to their AMF (Dietschmann)
  3. Alcohol Dependency Syndrome - RMC which means it has caused brain damage (Wood)
• Sentence

  If established, D is convicted of voluntary manslaughter not murder and so, there is a discretionary sentence.