Diminished Responsibility (s.2 Homicide Act, s.52 CJA 2009)

Diminished Responsibility (s.2 Homicide Act, s.52 CJA 2009)

1. Abnormality of mental functioning

   • 'A state of mind so different from that of ordinary human beings that the reasonable man would term it abnormal'
     • Byrne (1960)
   • cause of abnormality of mental functioning must arise from a 'recognised medical condition'
     • covers both psychological and physical conditions
     • there must be medical evidence

2. Substantially impaired

   • the abnormality of mental functioning must substantially impair the defendant's mental responsibility for his acts or omissions in doing or being a party to the killing
     • the jury must decide whether the impairment is of a substantial degree
   • substantial does not mean total, nor does it mean trivial or minimal (something in between)
     • Lloyd (1967)
   • the defendant's ability to do one of these three must be substantially impaired:
     • to understand the nature of his conduct
     • to form a rational judgement
     • to exercise self-control