Diminished Responsibility

• Definition

  DR is a partial defence to murder defined in s.2 homocide act 1957. Amended by the coroners and justice act s.2 2009
• Key element 1

  Is there an abnormality in mental functioning?

  So different from that of an ordinary person that a reasonable human being would term it abnormal (Bryne)
• Key element 2

  Did it arise from a recognised medical condition

  *Physical + Psychological e.g. depression, aspergers, paranoia

  *Medical evidence will be decisive (Brennan)

  *Excludes developmental immaturity and voluntary intoxication (Dowds)
• Key element 3

  Does it substantially impair Ds mental ability

  One must be substantially impaired

  a)To understand the nature of Ds conduct

  b)To form a rational judgement

  c)To exercise self control

  The jury apply their common sense to the meaning of "substantial"
• Key element 4

  Does it explain the killing

  *Causes Ds conduct or is a significant factor
• DR & Intoxication

  *Intoxication alone cannot support defence to diminished responsibility (Dowds)

  *Alcohol dependancy syndrome may support, e.g if alcoholism has lead to brain damage (Wood)

  *When D is drunk + suffering pre-existing abnormal mental functioning jury must ignore voluntary drinking