lc290 Partial Defences to Murder report - Law Commission

should be available to a serial child abuser at a time when child abuse is a grave
problem. Acting out of character may be a ground of mitigation, but it is hard to
see how it fits into a defence. If the defendant had no intent to kill and did not
foresee causing life threatening injury, so that death was not only unforeseen but
also unforeseeable, we can see a strongly arguable case for saying that he
should not be guilty of murder. 79 The proper approach to removing this
disfigurement of the law is to define murder in a rational way so that a rational
sentencing regime may apply.
5.76 On the other hand, knowledge of mental illness is a developing science and to tie
the definition to that contained in the Mental Health Act 1983 might be over
restrictive. 80 We see some attraction in the part of the version proposed by the
New South Wales Law Reform Commission, which refers to “an abnormality of
mental functioning arising from an underlying condition” and defines “underlying
condition” as meaning “a pre-existing mental or physiological condition other than
of a transitory kind”. 81
5.77 The New South Wales Law Reform Commission heard evidence that any
reference to “abnormality of mind” or a similar phrase should be omitted. 82 It
heard evidence that the phrase led to disputes amongst experts as to its exact
meaning and as to whether or not a particular mental condition could be said to
fall within it. It was suggested that, instead, diminished responsibility could be
defined solely in terms of whether or not the accused was affected as to capacity
to understand, to judge or to control her actions. In this way the expert’s attention
would be focused on describing the way the accused was affected at the time of
the killing.
5.78 The Commission was not persuaded. It felt that a formulation which did not
expressly link the defence to an underlying concept of mental impairment or
mental disorder would risk widening the ambit of the defence too far. Any person
who killed in a heightened emotional state might potentially plead the defence.
Instead, the Commission recommended the term “abnormality of mental
functioning arising from an underlying condition.” 83 The Commission preferred
“mental functioning” to “mind” because it had been informed that there had been
disagreements amongst expert witnesses as to the meaning of “mind”. 84
79 Presently such a person would be guilty of murder if he foresaw that some serious injury
was virtually inevitable, though not having it as his purpose (Woollin [1999] AC 82).
80 Section 1(2) of the Mental Health Act 1983 states: “In this Act: “mental disorder” means
mental illness, arrested or incomplete development of mind, psychopathic disorder and any
other disorder or disability of mind and "mentally disordered" shall be construed
accordingly;…”
81 Report on Partial Defences to Murder: Diminished Responsibility Report 82 (1997) para
3.43.
82 Ibid, at para 3.33 – 7.
83 Report on Partial Defences to Murder: Diminished Responsibility Report 82 (1997) para
3.43.
84 Ibid, at para 3.34.
102