Voluntary Manslaughter - Diminished Responsibility

Act

Originally set out in s2 Homicide Act 1957, modified by s52 Coroners and Justice Act 2009

Qualifications for defence

D was suffering from an abnormality of mental functioning which arose from a recognised medical condition, substantially impaired D’s ability to understand the nature of D’s conduct, OR form a rational judgement, OR exercise self control. It must also provide an explanation for the result

Abnormality of mental functioning

R v Byrne - ‘a state of mind so different from that of ordinary human beings that the reasonable man would term it abnormal’

Recognised medical condition - psychopathy

R v Byrne - sexual psychopath

Recognised medical condition - depression

R v Gittes

Recognised medical condition - Battered Spouse Syndrome

R v Ahluwalia

Recognised medical condition - epilepsy

R v Campbell

Recognised medical condition - ASD

R v Conroy

Recognised medical condition - Paranoid Personality Disorder

R v Squelch

Substantially impaired

R v Byrne - whether impairment was substantial is a question of degree and for jury to decide

R v Lloyd - substantial does not mean total, nor does it mean trivial, it is something in between

R v Golds - confirmed Byre and Lloyd

Understand his own conduct

Covers situations where D may not know what they are doing, could be where D suffers from delusions or has a lower mental age

Form a rational judgement

This is where the D may understand the nature of their conduct and therefore know what they are doing but they have a condition which means they cannot form a rational judgement to know that it is wrong, e.g. BSS (R v Ahulwalia)

Exercise self control

Simply where D can’t control their actions, R v Byrne

Provides an explanation for the result

Link to causation

Intoxication

Voluntary intoxication is not generally a defence for diminished responsibility - R v Dowds

Intoxication + AMF

R v Dietschmann, R v Kay - if D has an AMF and is intoxcated, must ask if D would do it had they not been drunk

Alcohol Dependency Syndrome

R v Wood, R v Stewart - Can be a defence, circumstantially - depends on how dependent, if it caused the AMF, etc.