The Mentally Vulnerable Defendant in the Criminal Justice System of England and Wales
: a Critical Investigation into Issues of Moral Agency, Criminal Responsibility and Effective Participation

Student thesis: Doctoral Thesis


This thesis, submitted for the award of Doctor of Philosophy by Completed Work, represents the collation and synopsis of eight publications, all relating to the protection of mentally vulnerable defendants within the criminal justice system in England and Wales, but with particular emphasis on moral agency, unfitness to plead and effective participation at trial. Following an investigation into moral agency and an examination of the proper attribution of criminal responsibility in relation to the offence/defence of infanticide and the partial defence of diminished responsibility, the focus moves on to unfitness to plead and the aspiration that only defendants who are capable of effective participation should have to stand trial. To otherwise require an unfit defendant to stand trial might result in a trial being unfair. The need for a defendant to be able to participate in a moral conversation in this context is highlighted. Engagement in a moral conversation is necessary in order for a defendant to be able to take responsibility for his criminal actions. Particular scrutiny is then paid to the untenable position of mentally vulnerable defendants being tried in the
magistrates’ courts, given the absence of a corresponding procedure to the trial of facts hearing in the Crown Court. Throughout the thesis, a critical examination of possible law reform is conducted, while the final two publications address the need for policy changes as an alternative to reform.
This collation and synopsis of publications advance existing knowledge by:
• examining the theoretical underpinning of the relevant mental condition defences and consistently requiring a defendant to be a moral agent in order to properly attribute criminal responsibility;
• responding to the Law Commission consultation process on unfitness to plead;
• adopting a different view to the Law Commission in recommending that any reform of the test for effective participation should be linked to a recognised medical condition;
• examining the legal aid system, the law relating to effective participation in the magistrates’ courts and the views of a small number of legal professionals in order to recommend that policy changes should take priority over law reform;
• addressing the NHS Liaison and Diversion Service as a key, crucial factor in supporting the mentally vulnerable defendant who is unable to effectively participate in his trial;
• developing a networking group for practitioners working with vulnerable defendants in the North East of England.
Date of Award1 Nov 2022
Original languageEnglish
Awarding Institution
  • Teesside University
SupervisorCatherine Crosby (Supervisor)

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