Report No. 35
Chapter XII
Diminished Responsibility
Topic Number 48
899. Diminished responsibility.-
A topic which merits some detailed discussion is the concept of "diminished responsibility", in relation to the law of homicide. This concept, borrowed from Scotland, has found a place in the Homicide Act, 1957, section 2. The section1 runs as follows:-
"2. Person suffering from diminished responsibility.-(1) Where a person kills or is a party to the killing of another, he shall not be convicted of murder if he was suffering from such abnormality of mind (whether arising from condition of arrested or retarded development of mind or any inherent causes or induced by disease or injury) as substantially impaired his mental responsibility for his acts and omissions in doing or being a party to the killing.
(2) On a charge of murder, it shall be for the defence to prove that the person charged is by virtue of this section not liable to be convicted of murder.
(3) A person who but for this section would be liable, whether as principal or as accessory, to be convicted of murder shall be liable instead to be convicted of manslaughter.
(4) The fact that one party to a killing is by virtue of this section not liable to be convicted of murder shall not affect the question whether the killing amounted to murder in the case of any other party to it.".
1. Section 2, Homicide Act, 1957.
900. The plea of diminished responsibility was intended to supplement the plea of insanity, i.e., to cover those cases in which the accused, though mentally incapacitated, did not come within the strict rules relating to insanity1.
1. 560 HC Debates, Col. 1153 et seq. and 1251 et seq. (November 15, 1956); 202 House of Lords Debates, Col. 364 (March 7, 1957).
901. The Royal Commission on Capital Punishment1, after an elaborate discussion of the doctrine, was unable to recommend its adoption in England. Though the doctrine as known to the Scottish law was confined to murder, the doctrine as known to the laws of several European countries touched all crimes, and not merely murder.
1. R.C. Report, pp. 143 to 144, paras. 411-413. Also see p. 426 et seq.
902. The conclusions which the Royal Commission reached on the subject1 may be thus summarised:-
(i) Diminished responsibility as known in Europe is a concept of general application relevant for all crimes and not only for murders or for capital offences. The forms of mental abnormality, including psychopathic personality, which may cause diminution of responsibility, are of common occurrence and are of importance in relation to a wide range of offences; and to consider whether the doctrine of diminished responsibility in this wide sense should be adopted in England would take the Commission far beyond its terms of reference2.
(ii) The Scottish doctrine of diminished responsibility on the other hand has a far narrower scope. It is confined to murder. It is a device to enable the courts to take account of a special category of mitigating circumstances in cases of murder and to avoid passing of sentence of death in cases where such circumstances exist. So radical an amendment of the law of England would not be justified for this limited purpose3.
(iii) The jury should, however, be empowered to take account of extenuating circumstances, so as to correct the rigidity which is the outstanding defect of the then existing law of capital punishment4.
1. R.C. Report, pp. 143 and 144, paras. 411-413.
2. R.C. Report, p. 144, para. 413.
3. R.C. Report, p. 144, para. 413.
4. R.C. Report, p. 208, para. 595.
903. However, the doctrine has been introduced by the Homicide Act, 1957. Under that Act1, even if a person is not technically insane within the meaning of the M' Naghten Rules, he is entitled to a lesser punishment if he shows that he was suffering from such abnormality of mind (whether arising from a condition of arrested or retarded development of mind or any inherent causes or induced by disease or injury) as has substantially impaired his mental responsibility for his acts and omissions in doing or being a party to the killing.
1. Section 2(1), Homicide Act, 1957 (5 & 6 Eliz. 2, C. 11).
904. As has been observed1, the effect of proof of diminished responsibility is to reduce the quality of the crime from murder requiring the obligatory sentence of death (if capital murder) or life imprisonment (non-capital murder) to manslaughter, where the sentence is in the discretion of the court, and may range from fine to any term of imprisonment to life imprisonment. The difference between this defence and that of insanity is-
(i) insanity results in acquittal and is a defence to every crime, while diminished responsibility is a defence only to murder, and merely reduces the crime to manslaughter:
(ii) diminished responsibility covers not only lesser forms of insanity but also different forms of insanity and mental abnormality not covered by the technical M'Naghten rules.
1. See the article on the Homicide Act by A.L. Armitage, 1957 Cambridge LJ 183, 187, 188, 189.
905. Scot Law.-
As would appear from the leading Scottish case of H.M. Advocate v. Braithwate, 1945 JC 55 extracted in R.C. Report, p. 349. even if a man charged with murder is not insane, still the Scottish law recognises that "if he was suffering from some infirmity or aberration of mind or impairment of intellect to such an extent as not to be fully accountable for his actions, the result is to reduce the quality of his offence-from murder to culpable homicide.
Approving a passage from the change in the case of Savage1, the court stated that there must be a state of mind which is bordering on, though not amounting to, insanity, and there must be a mind so affected that responsibility is diminished from full responsibility to partial responsibility. Again, citing previous cases, the court said that the question to be put to the jury was: "Was he, owing to his mental state, of such inferior responsibility that his act shoul.-have attributed to it the quality not of murder but of culpable homicide?".
1. Savage, 1923 JC 49,
906. As the court pointed out, stress had been laid, in all the formulations, upon the weakness of intellect, aberration of mind, mental unsoundness, partial insanity, great peculiarity of mind, and the like.
907. This exposition of the Scottish law has, after the passing of the Homicide Act, been expressly approved (for the interpretation of the defence as adopted in the Homicide Act) by the Court of Criminal Appeal1.
1. R. v. Dunbar, (1957) 3 WLR 330 (333): (1957) 2 All ER 737 (CCA).
908. Irresistible impulse.-
An English case of the Court of Criminal Appeal1 may be cited to illustrate how the defence has been actually applied in practice in England. There, the appellant was charged with the murder of a young girl whom he had strangled and whose dead body he had mutilated. He admitted the guilt, but pleaded the defence of diminished responsibility. The uncontradicted evidence of the senior medical witnesses was that the accused was a "sexual psychopath", and suffered from abnormality of mind, in that he had violent perverted sexual desires which he found it difficult or impossible to control.
Except when under the influence of such perverted sexual desires, he might be normal. They (the medical witnesses) were of the opinion that the killing was done under the influence of those desires, and that though he was not "insane" in the technical sense, his sexual psychopathy could be described as "partial insanity". The Judge directed the jury that if the appellant killed the girl under an abnormal sexual impulse which he found impossible to resist, but was otherwise normal, the section would not apply. The jury found him guilty of murder.
On appeal, on the ground of misdirection, the court allowed him the defence of diminished responsibility, and pointed out that "abnormality of mind" as used in the Homicide Act had to be contrasted with the time honoured expression "defect of reason" used in the M'Naghten rules, and appeared to be wide enough to cover the mind's activities in all its aspects, not only the perception of physical acts and matters and the ability to form a rational judgment as to whether an act is right or wrong, but also the ability to exercise the Will power to control physical acts in accordance with rational judgment".
The court pointed out that, before the passing of the Homicide Act, a person could escape liability for murder or any other crime requiring mens rea if he was insane, that is to say, "he was labouring under such a defect of reason from disease of the mind as not to know the nature and quality of the act and what he was doing, or if he did know it, that he did not know that he was doing wrong". That test was a rigid one because it related solely to a person's intellectual ability to appreciate the physical act that he is doing and whether it is wrong. If he has such intellectual ability, his power to control his physical acts by exercise of his will is irrelevant. Diminished responsibility, on the other hand, took note of every mental abnormality.
1. R. v. Byrne, (1960) 3 WLR 440 (444) (CCA).
909. The court proceeded to lay down certain other propositions (apart from the interpretation of "abnormality of mind", already noted) which may be summarised thus:
(i) Whether the accused .was suffering from abnormality of mind, as so interpreted, is a question for the jury. On this question medical evidence is no doubt of importance, but the jury is entitled to take into consideration all the evidence and not bound to accept the medical evidence.
(ii) The aetiology of the abnormality of mind, namely, that it arose from a condition of arrested development, etc., seemed to be a matter to be determined on expert evidence.
(iii) Assuming that there was abnormality of mind from the specified cause, the crucial question nevertheless was, "Was his responsibility for his acts in doing or being a party to the killing substantially impaired?" This was a question for the jury. Medical evidence was of course, relevant, but as a question involving a decision of "substantial impairment", it was a matter upon which juries may quite legitimately differ with doctors.
(iv) When the abnormality affects his control, the distinction between "he did not resist his impulse" and "he could not resist his impulse" is one which is incapable of scientific proof. These problems, in the present state of medical knowledge, are scientifically insoluble, and could be approached only in a broad common-sense way.
(v) On the evidence in the case, the accused was "what would be described in ordinary language as on the border line of insanity." The test of "border line" has been expressly approved by Lord Goddard1. He also pointed out that one cannot go into nice distinctions between mind and emotion, or intellect and emotion.
1. R. v. Spriggs, (1958) 1 All ER 300 (303,304) (CCA).
910. Illustrative cases.-
Another illustration of the application of this defence may be cited. In R. v. Matheson (1958) 2 All ER 87 (89). (Lord Goddard CT., Stanfield, Slade, Donovan and Havers JJ.) (CCA). the appellant who was fifty-two years old and a confirmed sodomite, murdered a boy of fifteen by smashing his head. He was convicted of capital murder, but on appeal, the Court of Criminal Appeal accepted the defence of diminished responsibility. One prison medical officer, one physical superintendent and one consulting psychiatrist agreed that, while he was not insane, his mind was abnormal and substantially impaired his mental responsibility. Giving the reasons for this conclusion, the prison medical officer stated that the prisoner's intelligence (measured by certain tests) was not more than 73, while that of a normal person would be 100.
The consulting psychiatrist called attention to the records showing that the appellant had, on many occasions, swallowed razor blades and inserted nails in his body. The physical superintendent agreed that the mental development was rather less than what one expects of a child of ten. Since this evidence was unrebutted, the defence had been satisfactorily proved. Evidence of premeditation could not rebut the defence, because "an abnormal mind is as capable of forming an intention and desire to kill as one that is normal; it is just what an abnormal mind might do."