Introductory facts:
- Two defences where D has committed murder
- D will raise one of the partial defences, diminished responsibility or loss of control
- If successfully raised (jury is satisfied that all of the elements/requirements for the defence are proved), the
defence will substitute the conviction with one for voluntary manslaughter (rather than murder) and the
judge has a full range of sentencing options open to them (from absolute charge to life imprisonment
DIMINISHED REPONSIBILITY
Source - Statutory
Definition – a state of mind in which a person's mental capacity is diminished in such a way that they lack the ability
to form the requisite intent for a crime
Partial defence to murder in S2 of Homicide but S52 of the Coroners and Justice Act amended S2, so the current law
is set out in this statute.
Element 1: Abnormality of mental functionality
S52(1) A person is not to be convicted of murder if they are suffering from an abnormality of mental functioning
D must prove on balance of probabilities that they were suffering from an AMF. We follow the same approach taken
in the old common law case of Byrne which said that “an abnormality of the mind” was a “state of mind so different
from ordinary human beings that the reasonable person would term is abnormal.
It covers the ability to exercise willpower or to control physical acts in accordance with rational judgement
Element 2: Arose from a recognised medical condition
It must be established that it is caused by a recognised medical condition rather than for instance, being intoxicated
(R v Hobson – battered wives syndrome)
Stringent medical test
I will follow the WHO (World Health Organization) of recognised conditions
D will need to adduce medical reports
Element 3: Substantially impaired D’s ability to do one or more of 3 things…
1 (A) those things are..
- To understand the nature of D’s conduct (this might apply to someone suffering from delusions or those with
learning difficulties)
- To form a rational judgement (this might apply someone who is suffering from paranoia or schizophrenia or
perhaps from battered woman syndrome)
- To exercise self control (this would apply to someone like Bryne, who killed a girl he met at the YWCA as he
could not control his urges – got DR)
The courts are likely to follow earlier decision like Llyod on what substantial impairment means ‘somewhere between
trivial and total impairment’ and later cases like Khan have confirmed this is a matter for the jury to decide
Element 4: The AMF caused by a RMC must provide an explanation for D’s conduct
2 (1) © provides an explanation for D’s acts or omissions in doing or being a party to the killing
There must now (since the 2009 Act) be a casual link between the AMF and D’s conduct
It does not have to be the only cause
- Two defences where D has committed murder
- D will raise one of the partial defences, diminished responsibility or loss of control
- If successfully raised (jury is satisfied that all of the elements/requirements for the defence are proved), the
defence will substitute the conviction with one for voluntary manslaughter (rather than murder) and the
judge has a full range of sentencing options open to them (from absolute charge to life imprisonment
DIMINISHED REPONSIBILITY
Source - Statutory
Definition – a state of mind in which a person's mental capacity is diminished in such a way that they lack the ability
to form the requisite intent for a crime
Partial defence to murder in S2 of Homicide but S52 of the Coroners and Justice Act amended S2, so the current law
is set out in this statute.
Element 1: Abnormality of mental functionality
S52(1) A person is not to be convicted of murder if they are suffering from an abnormality of mental functioning
D must prove on balance of probabilities that they were suffering from an AMF. We follow the same approach taken
in the old common law case of Byrne which said that “an abnormality of the mind” was a “state of mind so different
from ordinary human beings that the reasonable person would term is abnormal.
It covers the ability to exercise willpower or to control physical acts in accordance with rational judgement
Element 2: Arose from a recognised medical condition
It must be established that it is caused by a recognised medical condition rather than for instance, being intoxicated
(R v Hobson – battered wives syndrome)
Stringent medical test
I will follow the WHO (World Health Organization) of recognised conditions
D will need to adduce medical reports
Element 3: Substantially impaired D’s ability to do one or more of 3 things…
1 (A) those things are..
- To understand the nature of D’s conduct (this might apply to someone suffering from delusions or those with
learning difficulties)
- To form a rational judgement (this might apply someone who is suffering from paranoia or schizophrenia or
perhaps from battered woman syndrome)
- To exercise self control (this would apply to someone like Bryne, who killed a girl he met at the YWCA as he
could not control his urges – got DR)
The courts are likely to follow earlier decision like Llyod on what substantial impairment means ‘somewhere between
trivial and total impairment’ and later cases like Khan have confirmed this is a matter for the jury to decide
Element 4: The AMF caused by a RMC must provide an explanation for D’s conduct
2 (1) © provides an explanation for D’s acts or omissions in doing or being a party to the killing
There must now (since the 2009 Act) be a casual link between the AMF and D’s conduct
It does not have to be the only cause
