DIMINISHED
RESPONSIBILITY
The

defence of
Diminished Responsibility
(s.2, Homicide Act 1957, as amended by s.52,
Coroners & Justice Act
2009)

Procedural aspects
1.
2.
3.

4.

5.

Only available to charge of murder
Burden of proof on the defence (s.2(2))
Standard of proof on the “balance of probabilities” (R v Dunbar (1957))
If successful, results in conviction of manslaughter (s.2(3))
Pleas of guilty to manslaughter may be accepted if the evidence is “clear” (R v
Vinagre (1979))

Homicide Act 1957, s.2 (new version) (1) A person (“D”) who kills or is a party to the killing of another is not to be convicted of murder if D was suffering from an abnormality of mental functioning which:
(a)
(b)

(c)

arose from a recognised medical condition, substantially impaired D’s ability to do one or more of the things mentioned in subsection
(1A), and provides an explanation for D’s acts and omissions in doing or being a party to the killing.

Homicide Act 1957, s.2
(new version)
(1A) Those things are— a)to

understand the nature of
D’s conduct;
b)to form a rational judgment;
c) to exercise self-control.

Homicide Act 1957, s.2
(amended version)
(1B) For the purposes of subsection (1)(c), an abnormality of mental functioning provides an explanation for D’s conduct if it causes, or is a significant contributory factor in causing,
D to carry out that conduct.

DR: the 4 key elements
1.

2.

3.
4.

‘Abnormality of mental functioning’ A ‘recognised medical condition’ ‘Substantially impaired ability’
The abnormality ‘provides an explanation’ for the killing

1. ‘Abnormality of
Mental Functioning’
 No

further definition in the Act
 Replaces ‘abnormality of mind’ in the original version
 No requirement that the abnormality be inherited or present from birth (R v
Gomez (1964))

2. ‘Recognised Medical
Condition’




Replaces ‘condition of arrested or retarded development of mind or any inherent causes or induced by disease or injury’ in the original
s.2(1)
No further definition in the Act, but the following conditions were accepted under the original s.2(1)…

‘Recognised Medical
Condition’?







Adjustment disorder: R v Dietschmann
(2003)
Alcohol Dependency Syndrome (ADS): R v Tandy (1989), R v Inseal (1992), R v
Wood (2008), R v Stewart (2009)
Asperger’s syndrome: R v Jama (2004)
Battered Woman Syndrome (BWS): R v
Hobson (1998)

‘Recognised Medical
Condition’?




Depression: R v Seers (1984); R v
Gittens (1984); R v Ahluwalia (1992);
R v Hendy (2006); R v Swan (2006)
Epilepsy: R v Bailey (1961); R v
Campbell (1997)

Othello syndrome: R v Vinagre
(1979)
 Paranoia: R v Martin (2001)


‘Recognised Medical
Condition’?
Premenstrual syndrome: R v
Reynolds (1988)
 Psychopathy: R v Byrne (1960)
 Psychosis: R v Sanderson (1994)
 Schizophrenia: R v Terry (1961),
R v Moyle (2008), R v Erskine
(2009), R v Khan (2009)


Intoxication: irrelevant
R

v Fenton (1975):

“We do not see how self-induced intoxication can of itself produce an abnormality of mind.”


Intoxication is clearly not a
‘recognised medical condition’

Intoxication: irrelevant
R

v Gittens (1984):

“Where alcohol or drugs are factors to be considered [the jury] should be directed to disregard the effect of the alcohol or drugs upon [D]…”

Intoxication: irrelevant


R v Dietschmann (2003):
“The question is this: has [D] satisfied you that, despite the drink, his mental abnormality substantially impaired his mental responsibility for his fatal acts, or not? If he has satisfied you of that, you will find him not guilty of murder but … guilty of manslaughter. If he has not satisfied you of that, the defence is not available to him.”

Intoxication: irrelevant




R
R
R

v v v

Hendy (2006)
Robson (2006)
Swan (2006):

“Are the jury satisfied that, despite the drink or drugs, [D’s] abnormality of mind substantially impaired his mental responsibility for the killing?”

3. Substantial Impairment




The original test, that D’s ‘mental responsibility’ was