In Defense of the Insanity Defense and the Lindsey Clancy Jury

by Stephan Kinsella on September 12, 2026

[Cross-posted at StephanKinsella.com]

Everyone is freaking out about the Lindsay Clancy trial and the hung jury. Clancy, who had been having serious mental problems, strangled and killed her three children—Cora, 5, Dawson, 3, and Callan, 8 months—in Duxbury, Massachusetts, on January 24, 2023, and was on trial for first-degree murder.¹ She did not dispute that she killed them. Her defense was lack of criminal responsibility, commonly called an insanity defense. The jury, consisting of 9 women (all white) and 3 men, two white and one black, heard about five weeks of trial and then deliberated for seven days—roughly 38 to 40 hours—and could not reach a verdict. According to later interviews with jurors in the majority, 11 jurors would have voted to acquit on the basis of insanity, while the black male juror, the only non-white member of the panel, would have voted guilty.² A mistrial was declared on September 4, 2026. Because a hung jury is not an acquittal, prosecutors may retry the case.

The left basically defended Clancy, some on the grounds of postpartum psychosis, but some on ridiculous grounds—e.g., that she didn’t actually commit the murders, or that it was excused because of abuse by her husband or “the Patriarchy.” (She has admitted the killings; her own lawyer has rejected the online theories blaming her ex-husband. See NBC News.) The right, partly in response to these ridiculous left/feminist takes, started blaming women in general for siding with Clancy, saying this shows women should not have the right to vote, and so on. Many on the right and many libertarians celebrated the lone juror who refused to acquit even though, according to interviews with other jurors, he admitted that the prosecution had not proved its case beyond a reasonable doubt. (The holdout himself has not spoken publicly; that account comes from other jurors.)

(For a humorous depiction of the lone juror:

LMFAO!!!! 😂😂😂😂😂 pic.twitter.com/mXbsyqP3l1

— FOREVER 215 LBS (@Whamster98) September 12, 2026

Ryan Long:

Lindsay Clancy Juror Responds to Other Jurors TRASHING Him
)

Many on the right think the near-acquittal is an indictment of women or of feminism, even though two of the three male jurors also favored acquittal. As I see it, there are several problems with the take by the right and some libertarians here. First, from the fact that Clancy killed her children, they conclude that it’s obvious she should be found guilty and imprisoned for life. This shows no awareness of the complex nature of criminal trials.

First, in the American criminal law system, with its roots in English common law, to convict and punish a defendant the state (a) has the burden of proof, (b) the standard of proof is beyond a reasonable doubt (as opposed to lower standards such as preponderance of the evidence or clear and convincing evidence); (c) must use a jury if the defendant insists, (d) cannot compel the defendant to self-incriminate by testifying, (e) the jury must be unanimous, (f) double jeopardy prevents re-trial if there is an acquittal (a hung jury does not trigger double jeopardy), and (g) there are a number of other procedural protections and defenses available to the defendant, e.g. the state may not use illegally obtained evidence (the so-called exclusionary rule),³ the defendant must be read her Miranda rights, and so on.

In addition, the defendant normally can assert a defense of insanity. There are variations on the test, and on whether the defendant or the state bears the burden of proof. In some states, the defendant must affirmatively raise the defense, and prove it. In some states, it’s the M’Naghten rule. Its original wording is a proposed jury instruction:

that every man is to be presumed to be sane, and … that to establish a defence on the ground of insanity, it must be clearly proved that, at the time of the committing of the act, the party accused was labouring under such a defect of reason, from disease of the mind, as not to know the nature and quality of the act he was doing; or if he did know it, that he did not know he was doing what was wrong.

In other states, other tests are used. In Massachusetts, the defense is usually called lack of criminal responsibility. The test comes from Commonwealth v. McHoul, 352 Mass. 544 (1967), which adopted the American Law Institute’s Model Penal Code formulation rather than the older M’Naghten “right-from-wrong” rule.⁴ Under MPC § 4.01(1), a person is not responsible if, as a result of mental disease or defect, he “lacks substantial capacity either to appreciate the criminality [wrongfulness] of his conduct or to conform his conduct to the requirements of law.” M’Naghten is cognitive only: did the defendant know the act was wrong? McHoul adds a volitional prong: even if she knew it was wrong, could she control herself? Either failing is enough.

Three wording choices matter. “Substantial capacity” is less than total incapacity. “Appreciate” is broader than M’Naghten’s “know”—you can know an act is illegal in a thin sense and still not really grasp its wrongfulness. And the second prong covers the person who understands the act is wrong but, because of mental disease or defect, cannot stop.

That second prong is why Clancy’s postpartum-psychosis theory is legally intelligible in Massachusetts even if a juror thinks she “knew what she was doing.” Under M’Naghten, knowledge of wrongfulness would usually end the defense. Under McHoul, the Commonwealth still has to prove she also had substantial capacity to conform her conduct to the law.

Thus, under this rule, a person is not criminally responsible if, because of a mental disease or defect, she lacked substantial capacity either to appreciate the criminality or wrongfulness of her conduct or to conform her conduct to the requirements of the law. Either prong is enough. Once the defense is raised by some evidence, the burden shifts to the Commonwealth to prove beyond a reasonable doubt that the defendant was criminally responsible.⁵ At this point, the defendant does not have to prove insanity. See the Massachusetts model jury instructions on criminal responsibility.

Now, in a state-run criminal justice system, libertarians rightly tend to favor these high hurdles or barriers to criminal prosecution, even if this means prosecution of actually guilty criminals is difficult or even impossible; even if often a guilty person goes free. Blackstone put it: “it is better that ten guilty persons escape than that one innocent suffer.”⁶ Benjamin Franklin put the ratio even higher: “That it is better 100 guilty Persons should escape than that one innocent Person should suffer, is a maxim that has been long and generally approved.”⁷ I.e., we have a systematic preference for false acquittals over false convictions.⁸

This system reflects the widespread recognition—shared to an even greater degree by libertarians than by the general populace—that private crime is bad and a problem, but that an unbounded state is an even greater threat to life and liberty. We want it to be difficult for the state to convict. Proof beyond a reasonable doubt, a unanimous jury, the privilege against self-incrimination, and the bar on retrial after acquittal may benefit even guilty defendants, but that is the price of having constraints on the one institution that claims a monopoly of legitimate force and that can jail, impoverish, or kill. The Supreme Court treated the reasonable-doubt rule that way in In re Winship, 397 U.S. 358 (1970), calling it a “prime instrument for reducing the risk of convictions resting on factual error” and “a fundamental value determination of our society that it is far worse to convict an innocent man than to let a guilty man go free.” And we libertarians have even more reason to insist on that asymmetry. The state is not a private plaintiff seeking damages. It is an agency that, if under-constrained, will use the criminal process against enemies, dissidents, and whoever is convenient. High procedural barriers accept that some guilty people will walk in order to make that abuse harder.

In fact, most libertarians believe that even in an anarchist, private law society, any criminal punishment should still face high hurdles, such as proof beyond a reasonable doubt, and by a unanimous jury. Mere preponderance of the evidence would not be sufficient to incarcerate or inflict corporal punishment even in libertopia.

Moreover, many libertarians, including me, oppose not only the carceral state but also oppose even a private institutionalized penal justice system and instead favor one based on restitution.⁹ This is despite the fact that I believe that, in principle, punishment is justified and, in fact, that showing that there is a right to punish is how we show that victims do have rights.¹⁰

In any case, it makes sense, especially in a statist system, for it to be difficult for the state to imprison people. In addition, the law rightly recognizes degrees of culpability, and the libertarian law in an advanced society would surely draw analogous distinctions. Positive law grades unlawful killings as first-degree murder, second-degree murder, manslaughter, and, in many jurisdictions, negligent or reckless homicide. In this case the Massachusetts jury’s options, if it found Clancy criminally responsible, were first-degree murder, second-degree murder, or manslaughter. These are all actions: the defendant employed (causally efficacious) means that caused another’s death.¹¹ They are not all the same act of aggression. What differs is the end sought and how fully the death was intended—from a planned killing, to an unplanned but malicious killing, to a reckless or merely negligent one. That is why first-degree murder is punished more harshly than manslaughter or negligent homicide.

There is also a distinction made between human action and mere behavior. Striking someone in the head involuntarily during an epileptic fit or seizure is not action at all, while striking someone in the head intentionally, or negligently, is, even if the end result is the same in physical terms. The latter can be a tort or crime, but the former cannot as it is not even an action. Only actions give rise to liability and responsibility.¹²

And just as it makes sense to distinguish between a killing of another that is done negligently or with malice aforethought; or between involuntary behavior and intentional action; so it makes sense to consider the defendant’s state of mind, which is what the insanity rule does. Just as we might punish someone who planned a murder more hardly than someone who commits negligent vehicular homicide, we might want to treat differently someone who harms others due to some mental or psychological problem. And that is why variations of the insanity defense evolved on the common law.

All these gradations make a certain sort of practical and intuitive sense, but none of this is an empirical science. Adopting and implementing such standards is a matter of judgment, in the end. There is nothing else that a human system of justice can do. All this said, we cannot from our armchairs easily deduce exactly how such gradations and standards would develop over time in any workable criminal justice system.¹³ And we ought to be wary of advocating constructivist, rationalist new schemes from our armchairs and jettisoning past evolved rules. As Chesterton warned us, before you take down an old fence, you might want to try to figure out why it was erected. As I wrote in On the Role of Commentators and Codes and the Oracles of the Law:¹⁴

Thus we could imagine a given society adopting the general legal principles and some existing body or bodies of private law insofar as they are compatible with general libertarian principles. Rules of the Roman law or common law that are incompatible with the past bodies of private law will cautiously rejected, and the law going forward improved and moved in a more just direction.

Why cautiously? Because of humility, awareness of our limits, respect for the fact that the modern bodies of law took an accumulated two millennia to develop, and because of Chesterton’s Fence:

The positive Roman/European continental and Anglo-American common law would only be presumptively just, and would have to be scrutinized with respect to more fundamental or abstract or general libertarian principles, and ultimately discarded if found wanting. It would be no surprise if this were the case; lots of statist or other assumptions play into the reasoning of jurists over the centuries. It would be a surprise if mistakes never happened. Of course a sense of caution or humility in jettisoning long-established rules would be warranted. As Chesterton noted:

In the matter of reforming things, as distinct from deforming them, there is one plain and simple principle; a principle which will probably be called a paradox. There exists in such a case a certain institution or law; let us say, for the sake of simplicity, a fence or gate erected across a road. The more modern type of reformer goes gaily up to it and says, ‘I don’t see the use of this; let us clear it away.’ To which the more intelligent type of reformer will do well to answer: ‘If you don’t see the use of it, I certainly won’t let you clear it away. Go away and think. Then, when you can come back and tell me that you do see the use of it, I may allow you to destroy it.’¹⁵

For those libertarians impatient with “technicalities” and who want to discard evolved nuances like the insanity defense and just say “she did it; she fries!” or who say they would have voted to convict and disregarded the insanity defense and the judge’s jury instructions, keep in mind the scene in Robert Bolt’s famous play A Man for All Seasons, between Sir Thomas More More and his son-in-law, William Roper, in which More explains that the rule of law must protect everyone—even the wicked—because bending the law for convenience destroys the only protection society has against the powerful state:¹⁶

“William Roper: “So, now you give the Devil the benefit of law!”

Sir Thomas More: “Yes! What would you do? Cut a great road through the law to get after the Devil?”

William Roper: “Yes, I’d cut down every law in England to do that!”

Sir Thomas More: “Oh? And when the last law was down, and the Devil turned ’round on you, where would you hide, Roper, the laws all being flat? This country is planted thick with laws, from coast to coast, Man’s laws, not God’s! And if you cut them down, and you’re just the man to do it, do you really think you could stand upright in the winds that would blow then? Yes, I’d give the Devil benefit of law, for my own safety’s sake!”
― Robert Bolt, A Man for All Seasons: A Play in Two Acts; Goodreads quotes.

And the scene from the movie version:

***

So what is the bottom line? I do not think it it makes sense to reflexively criticize the 11 jurors who wanted to acquit, just because murder is heinous and deserves to be punished. First, we should be reluctant to endorse the carceral state and its punishment even of guilty actors—not for their sake, but for ours. Second, we should not oppose evolved nuances to state criminal law such as due process, jury trial, the exclusionary rule, the beyond a reasonable doubt standard of proof, and defenses such as the M’Naghten “insanity” defense or the MPC §4.01 “lack of criminal responsibility” defense. Given that we ought to favor such procedures as hurdles to state incarceration, what can the criticism of the 11 jurors be? They heard evidence and spent days deliberating. Is our criticism that Massachussets ought not have an insanity defense at all? Or that it has the wrong one? Or that the judge gave the wrong instructions? Or that the jury followed the judge’s instructions and attempted to follow the law? Or that they … got it wrong—that Clancy does not, factually, qualify for the lack of criminal responsibility defense? How would an outsider who was not privy to all the evidence provided to the jury during the 5 week trial be in a better position than the jury to make this assessment? Shouldn’t the fact that 11 of 12 jurors wanted to acquit, and the 12th apparently admitted there was “reasonable doubt”, despite their all sharing the common view that murder is reprehensible and ought to be punished, be given a bit of deference?