Introduction
The concept of justice is central to any legal system, yet its definition and application are fraught with complexity. Justice can be viewed through different lenses: procedural justice, which concerns the fairness of the processes by which law is applied, and substantive justice, which relates to the fairness of the legal outcomes and the laws themselves (Sanders and Young, 2007). This essay will argue that while the legal system in England and Wales provides a robust framework for procedural justice, its ability to deliver substantive justice is limited, particularly in complex criminal cases involving severe mental health conditions. By examining the issues raised by the recent US trial of Lindsey Clancy and comparing the legal approaches to those available under English law, specifically the defences of insanity and diminished responsibility, this essay will demonstrate the inherent challenges the law faces in balancing legal certainty with individualised justice.
The Challenge of Mental Health: The Case of Lindsey Clancy
The idea of justice is severely tested when the law confronts human tragedy compounded by mental illness. The 2024 case of Lindsey Clancy in Massachusetts, USA, provides a stark illustration of this challenge. Clancy, a labour and delivery nurse, was charged with the murder of her three young children. Her defence team argued that she was suffering from severe postpartum psychosis and, as a result, lacked criminal responsibility for her actions (Associated Press, 2024). They contended that her mental state was such that she did not appreciate the wrongfulness of her conduct and believed she was saving her children from a perceived terrible fate. The prosecution, conversely, argued that her actions were premeditated and that she was aware of their wrongfulness (Saltzman, 2024).
Under the law in Massachusetts, the legal test for insanity requires the jury to be satisfied that, as a result of a mental disease or defect, the defendant lacked the ‘substantial capacity either to appreciate the criminality [wrongfulness] of his conduct or to conform his conduct to the requirements of law’ (Commonwealth v. McHoul, 1967). Despite extensive expert testimony on Clancy’s mental state, the jury rejected the insanity defence and found her guilty of murder (Stelloh, 2024).
This outcome raises profound questions about the delivery of justice. Procedurally, Clancy received a trial by jury where evidence was presented and legal arguments were made. However, from a substantive justice perspective, the verdict is more contentious. It highlights the difficulty lay jurors face in evaluating complex and conflicting psychiatric evidence. Furthermore, it questions whether a rigid legal test for insanity, focused on cognitive appreciation of wrongfulness, can adequately account for the profound impact of conditions like postpartum psychosis, which can distort reality and volitional control. The verdict suggests a system prioritising a finding of legal responsibility over a nuanced understanding of medical culpability, which for many observers, falls short of a just result.
The English Law Approach: Insanity and Diminished Responsibility
If a case with similar facts to Lindsey Clancy’s were to be tried in England and Wales, the legal system would offer two main routes for the defence: the general defence of insanity and the special, partial defence to murder of diminished responsibility. An examination of these defences reveals a system that has evolved to address some, but not all, of the difficulties highlighted by the Clancy case.
The defence of insanity in England is governed by the M'Naghten rules, which date from the mid-nineteenth century (M'Naghten's Case (1843)). These rules establish a high threshold for the defence. The defendant must prove, on the balance of probabilities, that at the time of the act they were suffering from a ‘defect of reason’ which arose from a ‘disease of the mind’, and that as a result, they either did not know the nature and quality of their act, or they did not know that what they were doing was legally wrong (R v Windle [1952]).
The M'Naghten rules have long been criticised as medically outdated and overly restrictive (Jones, 1995). Their focus is almost exclusively on the defendant’s cognitive ability to know or understand, largely ignoring situations where a defendant may know their act is wrong but is unable to control their conduct due to their mental condition. It is plausible that a defendant suffering from severe postpartum psychosis, like Lindsey Clancy, might fail the M'Naghten test if the prosecution could show she had even a minimal awareness that her actions were legally wrong. The mandatory "special verdict" of "not guilty by reason of insanity" also leads to indefinite committal to a secure hospital, an outcome which many defendants fear, making the defence an unattractive option. This shows a clear limitation in the ability of this specific legal rule to deliver what many would consider substantive justice.
The Modern Approach: Diminished Responsibility
A more modern and frequently used defence in England and Wales is that of diminished responsibility. This is not a full defence but a partial defence, which, if successful, reduces a conviction from murder to manslaughter. The law is contained in section 2 of the Homicide Act 1957, as amended by section 52 of the Coroners and Justice Act 2009. To succeed, the defendant must demonstrate an abnormality of mental functioning which:
- arose from a recognised medical condition;
- substantially impaired their ability to understand the nature of their conduct, form a rational judgment, or exercise self-control; and
- provides an explanation for their role in the killing.
This modern formulation is significantly more flexible than the M'Naghten rules. The term ‘recognised medical condition’ allows the law to incorporate up-to-date psychiatric understanding, which would include severe postpartum depression or psychosis. Crucially, the 2009 amendment explicitly includes impairment of the ability to ‘exercise self-control’ as a potential basis for the defence. This directly addresses the volitional aspect of culpability that the insanity defence largely ignores. In a case like Clancy’s, a defence team in England would likely argue that the psychosis substantially impaired her ability to form a rational judgment and/or exercise self-control.
While the meaning of 'substantial' has been subject to judicial interpretation, with the Supreme Court in R v Golds [2016] UKSC 61 clarifying it means an impairment that is "weighty" and more than merely trivial, the defence provides a pathway to a conviction for manslaughter. This acknowledges a degree of legal responsibility but reflects the defendant’s reduced culpability. For many, this outcome represents a more just balance than the binary choice between a full murder conviction and a finding of insanity, as seen in the Clancy trial. It allows the law to deliver a more nuanced and proportionate response, thereby getting closer to achieving substantive justice.
Conclusion
The legal system’s capacity to deliver justice is not absolute. While it provides established procedures to ensure fairness in process, the attainment of just outcomes remains a profound challenge. The US case of Lindsey Clancy demonstrates the potential for a disconnect between a legally correct verdict and what might be considered a substantively just one, particularly when strict legal tests for insanity are applied to complex mental health crises.
In England and Wales, the law shows a clear evolution. The antiquated and narrow insanity defence, rooted in the M'Naghten rules, highlights the law's historical struggle to accommodate medical science. However, the modern partial defence of diminished responsibility offers a more sophisticated mechanism. It allows courts and juries to consider a wider range of mental health impacts, including the loss of self-control, and to reach a verdict that reflects reduced moral and legal culpability. To this extent, the English legal system has developed tools that are arguably better equipped to deliver a more nuanced form of justice in tragic cases of filicide arising from severe mental illness. Nevertheless, the reliance on a ‘battle of experts’ and the task imposed on lay jurors mean that even with more modern laws, the delivery of substantive justice can never be fully guaranteed and remains a point of significant tension within the legal system.
References
Associated Press (2024) ‘A Mass. mother is on trial, accused of killing her 3 kids. Her lawyers say she was mentally ill’, 28 January. Available at: [https://apnews.com/article/massachusetts-mother-kills-children-postpartum-psychosis-655f488d01168175d714652410a62308](https://apnews.com/article/massachusetts-mother-kills-children-postpartum-psychosis-655f488d01168175d714652410a62308)
Commonwealth v. McHoul, 352 Mass. 544 (1967)
Coroners and Justice Act 2009, s. 52
Homicide Act 1957, s. 2
Jones, D.G. (1995) 'The "disease of the mind" dithyramb in forensic psychiatry', The Journal of Forensic Psychiatry, 6(3), pp. 505-514.
M’Naghten’s Case (1843) 10 Cl & F 200
R v Golds [2016] UKSC 61
R v Windle [1952] 2 QB 826
Saltzman, E. (2024) ‘A prosecutor says Lindsay Clancy planned to kill her kids. A psychologist says she had psychosis’, Boston.com, 20 February. Available at: [https://www.boston.com/news/crime/2024/02/20/lindsay-clancy-trial-prosecutor-psychologist/](https://www.boston.com/news/crime/2024/02/20/lindsay-clancy-trial-prosecutor-psychologist/)
Sanders, A. and Young, R. (2007) Criminal Justice. 3rd edn. Oxford University Press.
Stelloh, T. (2024) 'Lindsay Clancy, Massachusetts mother who strangled her 3 children, is found guilty of murder', NBC News, 26 September. Available at: [https://www.nbcnews.com/news/us-news/lindsay-clancy-massachusetts-mother-strangled-3-children-found-guilty-rcna172828](https://www.nbcnews.com/news/us-news/lindsay-clancy-massachusetts-mother-strangled-3-children-found-guilty-rcna172828)

