lc290 Partial Defences to Murder report - Law Commission

what extent is the defence accommodating cases which it should not be and to
what extent is it failing to accommodate cases which it should be?
5.49 Other than the assertion of gender bias to which reference has already been
made, there was little evidence in the responses of a concern that the partial
defence of diminished responsibility was in general being applied too widely or
too narrowly. At the same time, concerns were expressed that it is a lottery and
that the outcome is more dependant on the persuasiveness of the psychiatrists
and the advocates, and the degree of sympathy which the jury has for the
defendant, than on any objective criteria.
The role of psychiatrists
5.50 The evidence we have received suggests that on the whole psychiatrists do not
have difficulty in forming and explaining to the jury their reasons for an opinion
whether the defendant was suffering from an abnormality of mind within section
2, although that term is broad and not legally defined.
5.51 The role of the psychiatrist is more difficult in relation to the second limb of the
section, ie whether the defendant’s abnormality of mind “substantially impaired
his mental responsibility for his acts or omissions in doing or being a party to the
killing”. It is apparent from Professor Mackay’s study that although a minority of
psychiatrists restrict themselves to the first limb of the section, almost 70%
express an opinion on that “ultimate question”. The psychiatrists to whom we
spoke expressed real reservations about being asked to give evidence about that
question, because it is not a matter of medical science, but in practice the
forensic process frequently draws them into doing so, implicitly if not explicitly.
Consultees’ views on alternative versions of the defence set out in the
Consultation Paper
5.52 In Consultation Paper No 173 44 we asked consultees whether they favoured:
(1) the present wording of section 2 of the 1957 Act;
(2) the alternative formula proposed in the Butler Report: 45
“Where a person kills or is party to the killing of another, he shall
not be convicted of murder if there is medical or other evidence that
he was suffering from a form of mental disorder as defined in
[section 1 of the Mental Health Act 1983, that is, “mental illness,
arrested or incomplete development of mind, psychopathic disorder
and any other disorder or disability of mind”] and if, in the opinion
of the jury, the mental disorder was such as to be an extenuating
44 Part XIII question 11.
45 Report of the Committee on Mentally Abnormal Offenders (1975) Cmnd 6244; in this Part
referred to as “the Butler Report”.
94