bits of law

Main Section

Criminal | Offences Against The Person

Voluntary Manslaughter: Liability

Model Answer | A Level

Download Adobe PDF Icon

Discuss liability for voluntary manslaughter

Voluntary manslaughter is a category of unlawful homicide, which applies where a defendant who would otherwise be guilty of murder can plead one of two specific partial defences. If a defendant successfully pleads a partial defence he may be found guilty of manslaughter, allowing more discretion in sentencing.

Diminished responsibility

Allows a partial defence for defendants suffering from wider range of mental health issues, under S52 of Coroners and Justice Act 2009(CJA 2009).

Abnormality of mental functioning

Defendant must be suffering anabnormality of mental functioning.

Case law developed under term abnormality of mind(Homicide Act 1957 ( HA 1957)).

Lord Parker defined abnormality of mind : .. a state of mind so different from that of ordinary human beings that the reasonable man would term it abnormal... (Byrne (1960)).

Recognised medical condition

There must be medical evidence to confirm an abnormality of mental functioning caused by the recognised medical condition.

recognised medical condition broad, covers physical and psychological conditions, including pre-menstrual tension(English (1981)), post natal depression (Reynolds (1998)) and Battered Woman’s Syndrome (Ahluwalia (1992)).

Substantially impaired

Defendant’s abnormality of mental functioning must substantially impair his mental responsibility for his conduct.

Substantial means more than minimal but not necessarily total and is a decision for a jury (Lloyd (1967)).

Impairment must be in relation to one of three aspects of defendant’s mental responsibility.

Ability to understand the nature of his conduct

Defendant is acting automatically and not aware of his conduct, may include delusions.

Form a rational judgement

Defendant does know the nature of his conduct but cannot form a rational judgement about his conduct, including paranoia (Martin [2002]).

Exercise self control

Defendant has a recognised medical condition which prevents him from exercising self control (Byrne (1960)).

Provides an explanation

Causal connection must be proved that the substantially impairment to the defendant’s mental responsibility provides an explanation for his conduct.


More complex if defendant was intoxicated at time of the killing, general rule that intoxication cannot support a defence of diminished responsibility (Di Duca (1959)).

Lord Hutton: .. the important question is: did that abnormality substantially impair his mental responsibility for his acts in doing the killing?.. (Dietschmann (2003)).

Fact defendant is intoxicated may be irrelevant (Hendy (2006) and Robson (2006)).

Alcohol Dependence Syndrome (ADS) is a recognised medical condition, a sufferer cannot control their drinking.

A key factor is whether defendant exercised control over their intoxication (Tandy (1989)).

Loss of control

Loss of control, under S54 of CJA 2009, replaces defence of provocation, found in the HA 1957.

Defendant must prove they lost self control, there was a qualifying trigger and person of the same sex and age would have reacted in the same way in the circumstances.

Loss of self control

Defendant must prove loss of control at the time of killing.

Qualifying trigger

There must be a qualifying trigger, defined under S55 of CJA 2009.

Fear of violence may be a qualifying trigger, defendant does not have to fear violence from victim, but cannot be a general fear, it must relate to a specific identified person. Under provocation it was not sufficient (Martin [2002]).

Things said or done may be a qualifying trigger, if they are proved to be extremely grave character and caused the defendant to have a justifiable sense of being seriously wronged. Tests were not part of provocation.

Sexual infidelity explicitly excluded as a qualifying trigger under S55(6)(c).

Revenge explicitly excluded under S54(4). As provocation required a sudden loss of control, if defendant had time to consider revenge, defence unavailable (Ibrahms and Gregory (1981)). However, if there was an element of revenge, then provocation was available (Baillie (1995)).

Standard of self control

Sex and age are the relevant characteristics to be considered, under S54 of CJA 2009. Principle developed under case law (Camplin [1978]) and (Attorney General for Jersey v Holley [2005]).

Circumstances of the defendant

Other circumstances of defendant may be taken into account in deciding whether a person with a normal degree of tolerance and self-restraint may have reacted in the same way.

Defendant killed victim, defendant had been sexually abused as a child and victim tried to sexually assault him. He successfully argued provocation (Hill (2008)).

This site is best viewed with style sheets (CSS) enabled and an up-to-date browser.