Proposed Reforms to Partial Defences and their Implications for Mentally Disordered Defendants

Abstract

Partial defences are special defences only available in England & Wales to defendants charged with murder. They include provocation, diminished responsibility, infanticide and killing pursuant to a suicide pact. These are known as the ‘voluntary manslaughters’ where homicide with intent otherwise sufficient for murder (‘malice aforethought’) is reduced to manslaughter because of defined mitigating circumstances. Provocation and diminished responsibility have proved most problematic and will be the focus of this article. The mitigating factors arise from abnormal mental states, and psychiatric evidence has been at the centre of disputes regarding these defences. In this journal, Kerrigan set out recent problems that have developed with provocation in case law. The degree to which mental disorder can be considered when deciding the standard of behaviour required of the defendant who pleads ‘provocation’ has fluctuated markedly in recent years. Diminished responsibility, on the other hand, has aroused concern, inter alia, over its expansive use to cover a wide range of mental conditions, and the frequency with which expert psychiatrists comment on the ‘ultimate issue’ of whether all limbs of the test are met. Both problems might be said to arise from vague terms in the statutory definition that are incompatible with contemporary psychiatric practice.

Following the controversial case of R v Smith (Morgan James), which permitted mental disorder a much greater effect on provocation, the United Kingdom Government asked the Law Commission to consider and report on the law and practice of the partial defences provided for by the Homicide Act 1957. This progressed to investigation into wider homicide law and a process of consultation and review which has now passed to the Ministry of Justice. This paper will outline briefly the review process before considering in greater detail the current proposals for new definitions of provocation and diminished responsibility. The Commission would like these to exist within a radically re-structured law of homicide. The implications for mentally disordered defendants and therefore expert psychiatric opinion will be considered.