The Lindsay Clancy Mistrial: Insanity, Justice, and a Public That Is Getting It Wrong

This was supposed to be my welcome-back-to-the-semester post. A roundup of new projects, plans for the fall, the usual beginning-of-year check-in. But the first week of school has already been genuinely chaotic, and more importantly, something happened in the news last week that I feel is worth a post. I’ve been following the Lindsay Clancy case, the Massachusetts woman charged with the murder of her three young children, for several years, and often mention it in my Forensic Psych class, but this summer Clancy’s trial began it suddenly been a national topic. The legal and public reaction to it is a perfect, if deeply painful, illustration of everything I am about to teach in my forensic psychology class, as well as some of my focus on true crime media. So, the welcome-back post will have to wait.

A content warning before we go any further: this case involves the deaths of three children. I am going to keep the factual details of the crime itself to the minimum necessary for context, because they are genuinely distressing and because the details are not really the point. The point is the law, the psychology, and what the public conversation around this case is revealing about how poorly most people understand both.

The Clancy Case

On January 24, 2023, in Duxbury, Massachusetts, Lindsay Clancy, a thirty-six-year-old former labor and delivery nurse, strangled her three children: five-year-old Cora, three-year-old Dawson, and eight-month-old Callan. Her husband, Patrick Clancy, had left the house briefly to run errands. Lindsay Clancy then jumped from a second-story window in what appeared to be a suicide attempt. She survived but was left paralyzed from the waist down. Since this, she has been held at Tewksbury State Hospital, a psychiatric facility, for the duration of her legal proceedings.

The defense has never disputed the facts of the case. What they argued, from the beginning, is that Lindsay Clancy was suffering from severe postpartum psychosis at the time of the killings, and this condition rendered her unable to appreciate the wrongfulness of her actions or to control them. The prosecution has argued that she understood what she was doing and that the killings were deliberate and planned. After a nearly six-week trial, the jury deliberated for seven days. Their note to Judge William Sullivan read, in the words reported by WBUR: “it is with a heavy heart that we report we are unable to come to a unanimous decision, and we will not be able to”. The jury was deadlocked eleven to one. Judge Sullivan declared a mistrial on September 4, 2026.

What is now known, because it was raised in the defense's emergency appeal to the Massachusetts Supreme Judicial Court, is that the lone holdout was allegedly refusing to apply the legal standard of reasonable doubt as instructed by the judge and required by law. The emergency appeal sought either to excuse that juror or to have the court inquire further. The Supreme Judicial Court denied the appeal. The mistrial stands. Plymouth District Attorney Tim Cruz will now have to decide whether to retry the case, negotiate a plea, or drop the charges. He will almost certainly retry, because the optics of not doing so are politically untenable. And that will cost the state approximately an additional thirty million dollars, produce another months-long proceeding that the Clancy family and the extended family of those children will have to live through again, and likely arrive at the same result, because the underlying facts and the law have not changed.

A Quick Refresher on the Insanity Defense

I covered the standards of the insanity defense in a previous post, and I would encourage you to read that if you want the full picture. But given that this case has now put those standards in the national spotlight, a brief refresher is worth including here.

The insanity defense, in its various forms, rests on a foundational principle that dates back much further than modern law. Roman legal theory recognized the concept of mens rea, or criminal intent: the idea that a crime requires not only a criminal act but a guilty mind. You have to intend to commit the crime, or be so reckless that your indifference to the harm constitutes a form of intent. Without mens rea, there is no crime in the full legal sense, only a harmful outcome. This is not a soft or modern notion. It is one of the bedrock principles of Western legal philosophy, and it has been embedded in common law for centuries (LaFave, 2017).

The modern history of the insanity defense in American and British law tends to begin with the M'Naghten case of 1843, in which a British court established a cognitive standard: a defendant could be found not guilty by reason of insanity if, at the time of the act, they did not know the nature and quality of what they were doing, or did not know that what they were doing was wrong. This is a strict, purely cognitive prong, focused entirely on knowledge at the time of the crime. It does not account for defendants who knew what they were doing was wrong but could not stop themselves (M'Naghten's Case, 1843).

That gap led to the development of other standards over the following century. The irresistible impulse test added a volitional element: even if a person knew their action was wrong, they could qualify for an insanity defense if they were unable to control their behavior. The Durham Rule, established in 1954, asked simply whether the criminal act was the product of mental disease or defect, which courts ultimately found too broad. The Model Penal Code standard, developed by the American Law Institute and commonly called the ALI standard, represents the most flexible formulation: a defendant is not criminally responsible if, as a result of mental disease or defect, they lacked substantial capacity either to appreciate the criminality of their conduct or to conform their conduct to the requirements of the law. Note the word either. Only one prong (cognitive or volitional) needs to be met (American Law Institute, 1962).

After the attempted assassination of President Reagan in 1981, John Hinckley Jr. was found not guilty by reason of insanity, which produced enormous public outrage and a Congressional response. The Insanity Defense Reform Act of 1984 dramatically narrowed the federal standard, eliminated the volitional prong entirely, and shifted the burden of proof from the prosecution to the defense. At the federal level, the defendant now has to prove insanity clearly and convincingly. Many states followed suit in the years after Hinckley (Insanity Defense Reform Act, 1984). Currently, four states, Kansas, Montana, Idaho, and Utah, have abolished the insanity defense entirely. The remaining forty-six states use some version of the cognitive or combined ALI standard.

Massachusetts Is Different

Here is what I did not know, and what I suspect most people discussing this case on social media did not know until a few weeks ago: Massachusetts is not only an ALI standard state, it also retains an older and significantly more defendant-favorable arrangement regarding the burden of proof. And under Massachusetts law, once the defense raises the question of the defendant's mental state at the time of the crime, the burden of proof shifts entirely to the prosecution. It is then up to the prosecution to prove beyond a reasonable doubt that the defendant was sane at the time of the crime according to the ALI criteria.

This is nearly the opposite of how it works in most of the country. Almost everywhere else, if you want to use an insanity defense, your legal team bears the burden of proving you were insane. In Massachusetts, the prosecution has to prove you were not. And because Massachusetts uses the ALI standard, which is already an either-or formulation, the prosecution must demonstrate beyond a reasonable doubt that Clancy both appreciated the wrongfulness of her conduct and was able to conform her behavior to the law. Prosecutors have to prove both. That is a genuinely high bar.

When I realized this structure, my first reaction was: I would be very surprised if Lindsay Clancy were found criminally responsible under this framework. I have been saying that throughout the trial, while also being appropriately nervous about being wrong. But based on the evidence that has been publicly presented, including testimony from forensic psychologists on both sides and the documented history of her postpartum mental illness, she appears to meet the criteria for lack of criminal responsibility in Massachusetts with considerable clarity. The eleven-to-one jury split seems to reflect that same assessment.

What the Public Is Getting Wrong

And now we come to the part of this that I find genuinely troubling, not just as someone who teaches and researches forensic psychology, but as a person who cares about justice and about how democratic societies talk about it.

The Lindsay Clancy case has become a national spectacle in a way that feels qualitatively different from other high-profile cases I have watched in recent years, including the Karen Read trial in Massachusetts last year. This one has gone national, and in some ways international, and it has broken along political lines in a way that is deeply clarifying about what is actually driving the public reaction. Conservative and men's rights communities are largely calling for conviction, questioning the legitimacy of the insanity defense as a category, and framing this as a case of a woman who murdered her children and is trying to escape accountability. Progressive and feminist communities are largely supporting the defense, framing this as a case about the catastrophic failure of postpartum mental health care in the United States, which is a real and serious failure that absolutely deserves attention. Both camps have are passionately arguing their points, as is typical of this kind of political binary, both are also talking past the actual legal question.

Podcasts are now devoting multiple episodes to breaking down the jury instructions and the expert witness testimony. Social media is full of people who have never studied the insanity defense in any context offering definitive opinions about whether Lindsay Clancy meets criteria (if they even know the criteria). And the most common refrain I am seeing from those calling for conviction is some version of: it does not matter why she did it. She killed her children and someone has to pay.

That refrain is worth taking seriously for a moment, because it reflects a genuine and understandable human impulse. Three children are dead. The grief and horror of that is real. But, that is an argument about retribution as an end in itself, and it requires abandoning the foundational legal principle that if punishment is to have a democratic purpose, it presupposes culpability. If Lindsay Clancy was genuinely out of touch with reality at the time of the killings, then punishing her does not serve justice. It serves only the psychological need to locate someone to blame for an outcome that is, in the legal and moral sense, a tragedy without a villain.

I sometimes use this analogy with my students: imagine a driver with no history of any medical issues who suddenly has a first-time epileptic seizure while behind the wheel. The car goes out of control and drives into a crowd. People are killed. The driver did it, in the causal sense. But the driver had no control over their body, no awareness of what was about to happen, and no intent to harm anyone. Most people, when presented with this scenario, will readily agree that charging this person with murder is unjust. The difficulty arises with mental illness because we are less comfortable extending the same logic there, and that discomfort is largely about stigma and misunderstanding rather than principle (Appelbaum, 1994).

There is also a specific misunderstanding circulating about what psychosis looks like that I want to address directly. A common argument in the anti-defense conversation has been that Clancy must have been sane because her actions appeared organized and deliberate. The prosecution leaned on this heavily. But this reflects a fundamental misconception about the relationship between psychosis and behavior. In disorganized psychosis, where a person's thinking and behavior appear chaotic and irrational, exists, but it is not the only presentation of psychotic illness. Paranoid delusions, in particular, tend to be highly organized and internally coherent. A person in the grip of a paranoid psychotic episode can plan, can execute a sequence of actions, can even appear calm, all while operating from a completely false and irrational belief system. The quality of the execution tells you nothing reliable about the presence or absence of psychosis. What matters is the underlying mental state, which is precisely what the forensic evaluators on both sides were hired to assess (Appelbaum & Grisso, 1995).

What This Means Going Forward

The mistrial leaves everyone in a difficult position. Lindsay Clancy will remain at Tewksbury State Hospital under psychiatric care while the district attorney's office decides next steps. If they retry the case, they will face the same law, the same burden of proof, and the challenge of empaneling a jury that has somehow not been saturated by months of national media coverage of a trial whose outcome was eleven to one in favor of acquittal. That is not an impossible task legally, but it is a deeply complicated (and expensive) one practically.

What I hope comes out of this, though I am honestly not optimistic given the trajectory of American public discourse around mental health and criminal justice, is a more informed conversation about what the insanity defense is actually for. It is not a loophole or a technicality. It is an expression of a moral principle that has been embedded in Western legal thought for centuries: that punishment requires culpability, and culpability requires intent. A person who commits a harmful act while in a psychotic episode is not the same, legally or morally, as a person who commits the same act with full awareness and intent. Treating them identically is not justice. It is retribution dressed up as justice.

The Andrea Yates case is the closest historical parallel. Yates drowned her five children in 2001 in Texas while suffering from postpartum psychosis. She was initially convicted of capital murder in 2002, a verdict that was later overturned on appeal (due to misconduct/error of the star prosecution witness). She was retried in 2006 and found not guilty by reason of insanity. She has been in a state psychiatric facility ever since. The legal process took five years and two trials to arrive at a result that most forensic clinicians considered obvious from the beginning. If the Clancy case follows a similar trajectory, and I fear it will, a family that has already suffered incomprehensibly will be made to suffer through it again while the public debates the case from a position of near-total ignorance about how the law actually works.

My charge to anyone reading this is the same regardless of where you land on this case: think about why you have the opinion you do and what facts support your opinion. If you believe Lindsay Clancy should be found not criminally responsible, be able to say why, specifically, in terms of what the law actually requires in Massachusetts and what the evidence actually shows. If you believe she should be convicted, ask yourself honestly whether your conviction rests on the legal standard or on the emotional need for someone to be held accountable for an situation that is almost unbearably painful. Both positions are worth examining carefully. One of them is consistent with the law as written. The other is a feeling, and feelings, however understandable, are not the basis on which criminal liability is determined.

Hug your people. This one is hard. I will keep an eye on it and update as things develop.

References and Bibliography

American Law Institute. (1962). Model penal code. American Law Institute.

Appelbaum, P. S. (1994). Almost a revolution: Mental health law and the limits of change. Oxford University Press.

Appelbaum, P. S., & Grisso, T. (1995). The MacArthur Treatment Competence Study I: Mental illness and competence to consent to treatment. Law and Human Behavior, 19(2), 105-126.

Insanity Defense Reform Act of 1984, 18 U.S.C. § 17 (1984).

LaFave, W. R. (2017). Criminal law (6th ed.). West Academic Publishing.

M'Naghten's Case, 8 Eng. Rep. 718 (H.L. 1843).

Melton, G. B., Petrila, J., Poythress, N. G., Slobogin, C., Otto, R. K., Mossman, D., & Condie, L. O. (2018). Psychological evaluations for the courts: A handbook for mental health professionals and lawyers (4th ed.). Guilford Press.

Steadman, H. J., McGreevy, M. A., Morrissey, J. P., Callahan, L. A., Robbins, P. C., & Cirincione, C. (1993). Before and after Hinckley: Evaluating insanity defense reform. Guilford Press.