The Law Commission

PART VIII

DIMINISHED RESPONSIBILITY: OTHER JURISDICTIONS

8.1     In this Part we summarise, in tabular form, the law relating to diminished responsibility and/or comparable defences in seven other countries. The summary is drawn from the academic papers contained in Appendices A – F.^[1] Professor Yeo's paper (appendix A), relating to Australia and India, considers the four Australian jurisdictions which have the defence of diminished responsibility. Of the other five Australian jurisdictions^[2] that do not have the defence, only the position in Victoria is summarised, due to the recent reconsideration of the issue in that State.
8.2     Overall, the law in eleven jurisdictions is considered in this Part. These jurisdictions fall into two groups: those that do have a specific defence referred to as diminished responsibility and those that do not. Those jurisdictions that do have the defence are summarised from both substantive and procedural perspectives, concentrating on those elements that are most relevant to the current terms of reference.
8.3     Those jurisdictions that do not have the defence are examined for the presence of other defences that may affect persons currently falling within the English definition of diminished responsibility. Particular reference is made to other mental incapacity defences. Further, any proposed reforms to the current status of mental incapacity defences or their equivalent are summarised.

Summary conclusions

8.4     The information contained in the ensuing tables primarily demonstrates the lack of consistency in addressing the issue of reduced mental capacity in homicide cases. Of the eleven jurisdictions considered, five have a partial defence of diminished responsibility. The remaining six do not have either the defence or a significantly comparable equivalent.
8.5     This incongruity indicates the difficult nature of the concepts involved. The New Zealand Law Commission expressly rejected the notion of a diminished responsibility partial defence on the basis that it was too problematic to define successfully. In reaching this conclusion they allude specifically to the current English law defence and the way in which they believe this has not and would not be satisfactorily remedied by the alternatives they consider.^[3] They adopt the position that the issue of diminished capacity is one better dealt with at the sentencing stage, and simultaneously recommend the replacement of the mandatory life sentence for murder with sentencing discretion.^[4]
8.6     Of those countries that have incorporated a partial defence of diminished responsibility, there is no one consistent formulation. The terminology used varies in focus from the comprehension of the accused as to the nature and quality of his or her actions, to the control he or she was able to exert over his or her actions, to whether the effect of the impairment is sufficient to reduce murder to manslaughter. Of the countries with the partial defence only Scotland is currently considering reform. This is also the only jurisdiction where the defence is based entirely on common law.
8.7     Those countries without the defence address the issue of mental incapacity short of insanity in a variety of ways. Ireland has extended the concept of insanity to incorporate 'volitional insanity'.^[5] In contrast Canada and New Zealand allow evidence of mental disorder short of insanity to be introduced to support a contention of no intent. Of the six jurisdictions without the defence, four have expressly rejected or are not considering any reform to introduce it.^[6] Of the remaining two, one (Ireland) is currently considering a Bill to incorporate it, and the other (Australia: Victoria) is undertaking a general review of homicide.
8.8     To differing extents, all of the jurisdictions considered recognise the issue of the non-insane mentally disordered killer. Whether this is expressly addressed in statute or whether it is subsumed within other categories of defences varies significantly. Despite the relative incongruity, only three of the jurisdictions are currently considering reforms. Whether this is indicative of a general contentment with the present status of the law in the remaining jurisdictions, or a recognition that there is no viable formulation of the diminished responsibility defence, as decided by the New Zealand Law Commission, is unclear.

Note 1    See Para 5.1.    [Back]

Note 2    Homicide is not a crime at federal level, therefore discussion in Part V on the law of provocation focuses on eight rather than nine jurisdictions.    [Back]

Note 3    New Zealand Law Commission, Some Criminal Defences with Particular Reference to Battered Defendants, Report 73, May 2001, para 137.    [Back]

Note 4    Ibid, paras 137-151.    [Back]

Note 5    This concept covers certain serious mental diseases which do not prevent an accused from understanding the nature and quality of an act, but which may still prevent him or her from exercising a free volition as to whether he should or should not do that act. See Appendix C, Irish Law Reform Commission, paras 10 – 12.    [Back]

Note 6    Canada, India, New Zealand and South Africa.    [Back]