The insanity defence: International and comparative perspectives By R. Mackay, W. Brookbanks (Ed.), Oxford: Oxford University Press. 2022. pp. 416. £90.00 (hbk). ISBN: 9780198854944

Highly criticised and widely discussed, there is a general consensus that the defence is in dire need of reform: from its stigmatic title to the narrow interpretations of both limbs of the Rules, it is a rarely used and outdated defence. Despite the vast amount of commentary on this topic, The insanity defence: International and comparative perspectives, part of the Oxford Monographs on Criminal Law and Justice series, provides a fresh outlook on this defence, collating internationally renowned experts and a diverse range of jurisdictions into one edited collection.

The book aims to explore the insanity defence in other jurisdictions and to ‘point the way to a balanced assessment of how the insanity defence might be altered and improved’ (p.369). Both of these aims are, in my view, achieved. The breadth of jurisdictions covered within this collection provides the reader with a variety of alternative interpretations or possible amendments to the M'Naghten Rules, as well as cautioning against directions in which the defence ought not to go.

The insanity defence begins with a critique of the M'Naghten Rules in England and Wales and an exploration of reform proposals, subsequently moving on to address other common law jurisdictions, including: Scotland, New Zealand, Canada and the United States. Beyond this, four civil law jurisdictions are covered: France, Germany, the Netherlands and Norway, before consideration is made of the insanity defence in China and under international criminal law.

Of the civil law jurisdictions, Meynen, in Chapter 12, suggests that the open criterion set out in the Dutch Criminal Code creates the potential for ‘disparity’ (p.285), of which we should take heed. The tragic mass killing by Anders Breivik in Norway triggered a move away in that country from what was arguably a successful medicalised model of the insanity defence, demonstrating the dangers of ‘knee-jerk’ legislation in the wake of tragedy. It is hoped that Gröning's suggestion that the move is less significant than initially suspected proves to be correct (p.314).

Key themes emerging from this collection concern the ubiquity of the M'Naghten Rules, versions of which are still used, albeit more flexibly, in many jurisdictions. Ireland, for example, has an additional volitional element. The Canadian Supreme Court has a ‘pragmatic and somewhat chameleon interpretation of the Rules (p.122), while Australia seems to offer ‘an incoherent patchwork of inconsistent provisions’ (p.196), many of which also reflect the Rules. Even Article 31(1)(a) of the Rome Statute ‘evokes’ the Rules (p.344), despite the International Criminal Court having no accepted procedure for detention in the highly unlikely event of a successful plea.

Other themes in this book include the willingness of most jurisdictions to link a mental disorder to the defendant's conduct, as well as similarities in disposal outcomes across the jurisdictions, which point to protection of the public and treatment rather than punishment. Although versions of the Rules continue to be employed in many jurisdictions, the stigmatic title of the defence is less widely used. Scotland, for example, no longer employs the term ‘insanity’, although s.51A of the amended Criminal Procedure (Scotland) 1995 Act does not provide an alternative title.

A personal highlight is Rauxloh's, ‘Insanity in German criminal law’. In Germany, a mental disorder, rather than providing a defence, allows for an exclusion of criminal responsibility, translated as an ‘inability to be allocated blame’ (p.247). This chapter provides a fascinating analysis of the interplay between free will, moral agency and medicine. It also addresses the complex issue of incapacity where it is brought about by the defendant, a theme which recurs in several chapters, most notably in relation to the increasing use of methamphetamine in New Zealand (ch. 7).

The law in China, outlined in Chapter 14, bears least resemblance to the current insanity defence in England and Wales but, with high-profile or serious criminal offenders being ‘more likely to receive a death sentence despite their medical conditions’ (p.325), and two centuries’ worth of stigma to challenge, this is hardly surprising. Further areas for development might include comparative studies of the insanity defence in African, South American and Middle Eastern countries.

The rallying cry for reform resonates throughout the collection. Ormerod and D'Souza, in Chapter 3, summarise: ‘A civilised society should strive to define its criminal laws so that they are based on sound principles and policies that respect basic human rights and dignity’ (p.46), while Morse points out that: ‘conviction of a defendant who is morally innocent is legally objectionable. A just criminal law would not permit this’ (p.211). Mackay suggests that the Supreme Court could adopt a more flexible interpretation of the Rules (p.43). Certainly, other jurisdictions have been prepared to do so. In view of the flexibility shown towards the M'Naghten Rules elsewhere, Mackay and Brookbanks have amply demonstrated that this is both achievable and, absent legislative changes, desirable.

Despite the quality of the contributions, this collection is not for the faint-hearted. As well as taking in the nuances between different approaches to the M'Naghten Rules (the difference, for example between knowledge, appreciation, or capacity to appreciate), the reader must also navigate different legal systems, evidential burdens and theoretical approaches to criminal responsibility. For the steadfast reader, the rewards are immense, offering a valuable trove to those with a keen interest in the area.