Eleven to One: The Lindsay Clancy Trial and the Case for a Graded Insanity Defense

Author: Kenneth Smith, Senior Editor

During late summer 2026, the public was enthralled by the legal and sociopolitical events surrounding the Lindsay Clancy trial. This piece offers only a brief synopsis of Clancy’s story.[i] In January 2023, less than three weeks after she was discharged from a psychiatric hospital for postpartum psychosis, Clancy strangled her three very young children in the basement of their home in Duxbury, Massachusetts, and then attempted to take her own life.[ii] Dr. Phillip Resnick, an expert psychiatrist who evaluated Clancy after the murders, determined she did not commit this crime out of malice, but instead due to auditory hallucinations and severe suicidal tendencies.[iii] These suicidal tendencies caused a delusion so powerful it was described as an out-of-body force pushing her through the motions of killing her children.[iv] Dr. Resnick was only one piece of the Defense case-in-chief.[v]

At the end of the  trial, the jury spent thirty-eight hours in deliberation spread across seven days.[vi] It was widely reported that during these deliberations, eleven jurors were prepared to find Clancy not guilty by lack of criminal responsibility, and one juror was not.[vii] Unable to come to a unanimous decision, the jury forced Judge William Sullivan to declare a mistrial.[viii] It may be natural to read of the split in the jury as the responsibility of a lone juror, but in Clancy’s case, the law simply left the twelve jurors without a workable option.

Two jurisdictions with legal traditions similar to those of the United States, England and Canada, recognize an alternative outcome in cases of suspected mental impairment. Both grade homicide by the degree of a defendant’s mental impairment rather than treating criminal responsibility as all or nothing.[ix] England offers a partial defense of diminished responsibility that reduces murder to manslaughter without requiring a defendant to satisfy the insanity standard.[x] Canada’s law functions similarly to that of England’s.[xi] American law has no equivalent.[xii] Part I highlights why Massachusetts offers one of the most generous forms of the insanity defense in the country, and why that generosity still left the Clancy jury without a proper verdict. Part II argues that England’s diminished responsibility defense, rather than the infanticide statutes that preceded it, is the fix for that gap.

I. Massachusetts – The Most Generous Insanity Standard in the Country

In 1967, the Supreme Judicial Court of Massachusetts rendered its decision in Commonwealth v. McHoul, holding that a Massachusetts defendant is not criminally responsible if they lacked substantial capacity either to appreciate the wrongfulness of their conduct or to conform their conduct to the requirements of law as a result of mental disease or defect.[xiii] It is under this test that Clancy’s defense counsel, Kevin Reddington, was able to establish a viable defense strategy, arguing that postpartum psychosis, the severe delusion described by Dr. Resnick, prevented her from conforming her conduct to the requirements of the law.[xiv]

The Massachusetts law in this area is unusual in how it allocates the burden of proof. In most states, the defendant must prove a lack of responsibility, but in Massachusetts, once the issue of insanity is fairly raised, the Commonwealth bears the burden of disproving it beyond a reasonable doubt.[xv] The jury may also be instructed that an acquittal would result in commitment rather than release.[xvi] While the Clancy case involved all of these insanity defense advantages, the jury was still hung after a week of deliberation.[xvii]

The jury verdict slips contained five options: (1) not guilty, (2) not guilty by lack of criminal responsibility, (3) guilty of first-degree murder, (4) guilty of second-degree murder, or (5) guilty of manslaughter.[xviii] The first-degree murder charge in Massachusetts can be proven under more than one theory. The jury in the Clancy case was instructed on two.[xix] The first, deliberate premeditation, requires the Commonwealth to prove that the defendant intended to kill and reached that decision after a period of reflection.[xx] Evidence of mental impairment is admissible, and a jury crediting evidence of mental impairment may find the Commonwealth has failed to prove premeditation, which downgrades the charge to second-degree.[xxi] The second theory to prove first-degree murder, extreme atrocity or cruelty, requires only malice aforethought—the same mental state required for second-degree murder.[xxii] What elevates the charge to first-degree under this theory is a set of factors announced in Commonwealth v. Cunneen, six of which describe the manner of the victim’s death rather than the mind of the defendant.[xxiii]

A second-degree murder charge hinges on malice aforethought, which in Massachusetts may be established in any of three ways.[xxiv] The Commonwealth may prove an intent to kill, an intent to cause grievous bodily harm, or an intent to do an act which, in circumstances known to the defendant, a reasonable person would have known created a plain and strong likelihood death would result.[xxv] However, postpartum psychosis may cause women to be lucid one minute, and suffer from intense delusions the next.[xxvi] Lindsay Clancy’s psychosis defense, therefore, cast significant doubt over whether she was even aware of her actions when the events of that day unfolded.

The final option on the jury slip was manslaughter.[xxvii] Judge Sullivan defined this charge in terms of wanton or reckless conduct.[xxviii] That definition sat awkwardly with the facts, because neither party argued that the deaths were accidental.[xxix] Wanton or reckless conduct assumes some control over conduct is retained by the defendant, and Clancy’s delusions were characterized as an out-of-body force.[xxx] At a minimum, Clancy’s insanity defense casts doubt over the required intent across all three charges; at its most effective, it entirely absolves her of criminal responsibility for a devastating tragedy.

What the verdict slips reveal is a gap that the McHoul standard cannot close. Murder charges hinge on premeditation and the atrocity of the death. Manslaughter turns on whether the conduct could be controlled.[xxxi] None of these categories consider impairment. Evidence of mental illness can defeat an element and move a defendant one rung down the ladder, but the Massachusetts Supreme Judicial Court has rejected diminished capacity as a doctrine in its own right.[xxxii] The result is that a juror who believed Clancy was gravely ill, but not so ill as to deserve a complete acquittal, had no equivalent verdict available. Such a juror could move the verdict from first-degree murder to second-degree, and in doing so would still call a mentally ill mother a murderer and send her to prison for life. Other common law jurisdictions have confronted this same problem; Part II considers their solutions.

II. England and Canada Built a Middle Position

Laws recognizing the effect of postpartum mental illness on criminal responsibility are neither new nor experimental. The Infanticide Act 1938, which governs in England and Wales, provides that a woman who kills her child under the age of twelve months is guilty of infanticide rather than murder if, at the time of the act, “the balance of her mind was disturbed” because she had not fully recovered from the effects of giving birth or of lactation.[xxxiii] Canada adopted nearly identical language a decade later in section 233 of its Criminal Code. Both jurisdictions treat the resulting offense far more leniently than murder.[xxxiv] These statutes would not have resolved the Clancy case, however. They only apply to children under twelve months. Clancy’s children were Cora, age five; Dawson, age three; and Callan, age eight months, so the graded offense would have been available on just one indictment.[xxxv]

England offers a second option. Section 2 of the Homicide Act 1957, as amended by section 52 of the Coroners and Justice Act 2009, establishes the partial defense of diminished responsibility.[xxxvi] A defendant is not to be convicted of murder if they were suffering from an abnormality of mental functioning which (1) arose from a recognized medical condition, (2) substantially impaired their ability to understand the nature of their conduct, to form a rational judgment, or to exercise self-control, and (3) provides an explanation for their acts in carrying out the killing.[xxxvii] A defendant who establishes the defense is convicted of manslaughter instead, which carries a discretionary sentence rather than a mandatory one.[xxxviii]

Section 2 of the Homicide Act 1957 contains no age requirement for the victim, so it would have applied to all three of the Clancy children.[xxxix] It is not limited to women, which answers the objection that infanticide statutes rest on  paternalistic assumptions about female offenders.[xl] It also does not ask whether childbirth caused the illness, but rather whether a recognized medical condition substantially impaired one of three specified capacities.[xli] The bipolar disorder with postpartum psychosis that Dr. Resnick described at Clancy’s trial would qualify.[xlii]

Consider how the Clancy deliberations might have proceeded under such a rule. The eleven jurors finding that Clancy lacked criminal responsibility could have returned that verdict. The single juror who did not could have voted instead for a verdict holding her responsible in part, recognizing her illness as a substantial impairment without excusing the killings altogether.

Massachusetts should adopt a partial responsibility verdict modeled on section 2. Such a verdict would not have excused what happened in Duxbury, and it would not have guaranteed a unanimous jury. It would have given the jury a way to record what eleven of its members appear to have concluded, which is that Lindsay Clancy was gravely ill and that her illness bore on her blameworthiness. The objections to grading responsibility in this way are substantial, and they deserve more attention than this piece can offer.[xliii] The question is also no longer academic. At a hearing set for September 29, 2026, Clancy’s counsel asked the court for a required finding of not guilty by reason of lack of criminal responsibility and was denied.[xliv] They have now moved to dismiss the indictments on double jeopardy grounds, and the Commonwealth has still not said whether it will try her again.[xlv] If it does, a second jury will receive the same five verdict slips as the first, and nothing in Massachusetts law will have changed to help it.

[i] Leah Willingham & Michael Casey, Lindsay Clancy’s Defense Rests After Testimony on Postpartum Psychosis, PBS Newshour (Aug. 21, 2026).

[ii] Judge Declares Mistrial in Clancy Case After Jurors, with “Heavy Heart,” Fail to Reach Verdict, WBUR News (Sept. 4, 2026), https://www.wbur.org/news/2026/09/04/lindsay-clancy-murder-trial-verdict-massachusetts.

[iii] What Each Mental Health Expert Said in the Lindsay Clancy Trial, NewsNation (Aug. 2026), https://www.newsnationnow.com/crime/lindsay-clancy-murder-trial-mental-health-experts/.

[iv] Willingham & Casey, supra note 1.

[v] What Each Mental Health Expert Said, supra note 3.

[vi] Judge in Lindsay Clancy Trial Declares Mistrial, CNN (Sept. 4, 2026), https://www.cnn.com/2026/09/04/us/live-news/lindsay-clancy-trial.

[vii] Id.

[viii] Id.

[ix] Infanticide Act 1938, 1 & 2 Geo. 6 c. 36, s. 1 (Eng.); Criminal Code, R.S.C. 1985, c. C-46, s. 233 (Can.).

[x] Homicide Act 1957, 5 & 6 Eliz. 2 c. 11, s. 2 (Eng.), as amended by Coroners and Justice Act 2009, c. 25, s. 52.

[xi] Criminal Code, R.S.C. 1985, c. C-46, ss. 233, 237 (Can.).

[xii] Commonwealth v. Johnson, 374 Mass. 453, 462–65 (1978); see Commonwealth v. Grey, 399 Mass. 469, 470 (1987).

[xiii] Commonwealth v. McHoul, 352 Mass. 544, 546–47 (1967).

[xiv] Lindsay Clancy Trial Testimony Live Updates, NBC News (Aug. 2026), https://www.nbcnews.com/news/us-news/live-blog/lindsay-clancy-trial-testimony-live-updates-rcna594438.

[xv] See Clark v. Arizona, 548 U.S. 735, 752–53 (2006); Commonwealth v. Keita, 429 Mass. 843, 849 (1999).

[xvi] Commonwealth v. Mutina, 366 Mass. 810, 823 (1975).

[xvii] Judge in Lindsay Clancy Trial Declares Mistrial, supra note 6.

[xviii] Eric Levenson, Lauren del Valle & Elise Hammond, What Is the Difference Between Murder and Manslaughter?, in Lindsay Clancy’s Jury Starts Deliberations in Her Murder Trial, CNN (Aug. 27, 2026), https://www.cnn.com/2026/08/27/us/live-news/lindsay-clancy-trial-closing-arguments.

[xix] Mass. Gen. Laws ch. 265, § 1 (2024); Levenson et al., supra note 17.

[xx] Mass. Ct. Sys., Model Jury Instructions on Homicide: VII. Involuntary Manslaughter (2018), https://www.mass.gov/info-details/model-jury-instructions-on-homicide-vii-involuntary-manslaughter.

[xxi] Commonwealth v. Gould, 380 Mass. 672, 680–86 (1980).

[xxii] Commonwealth v. Semedo, 422 Mass. 716 (1996).

[xxiii] Commonwealth v. Cunneen, 389 Mass. 216, 227 (1983); see Commonwealth v. Berry, 466 Mass. 763 (2014) (Gants, J., concurring).

[xxiv] Commonwealth v. Stewart, 460 Mass. 817, 826 & n.9 (2011).

[xxv] Id.

[xxvi] Veerle Bergink, Natalie Rasgon & Katherine L. Wisner, Postpartum Psychosis: Madness, Mania, and Melancholia in Motherhood, 173 Am. J. Psychiatry 1179 (2016).

[xxvii] Levenson et al., supra note 17.

[xxviii] Commonwealth v. Welansky, 316 Mass. 383, 399 (1944); Mass. Ct. Sys., supra note 19.

[xxix] Lindsay Clancy Trial: What Each Possible Verdict Would Mean, NewsNation (Sept. 4, 2026), https://www.newsnationnow.com/crime/lindsay-clancy-possible-verdicts/.

[xxx] Willingham & Casey, supra note 1.

[xxxi] Mass. Gen. Laws ch. 265, § 1 (2024); Welansky, 316 Mass. at 399.

[xxxii] Johnson, 374 Mass. at 462–65; Grey, 399 Mass. at 470.

[xxxiii] Infanticide Act 1938, 1 & 2 Geo. 6 c. 36, s. 1 (Eng.).

[xxxiv] Criminal Code, R.S.C. 1985, c. C-46, ss. 233, 237 (Can.); Infanticide Act 1938, s. 1(1) (Eng.); see R v Borowiec, 2016 SCC 11, [2016] 1 S.C.R. 80 (Can.).

[xxxv] Levenson et al., supra note 17; Infanticide Act 1938, s. 1 (Eng.); Criminal Code, R.S.C. 1985, c. C-46, ss. 2, 233 (Can.).

[xxxvi] Homicide Act 1957, supra note 10.

[xxxvii] Id. s. 2(1), (1A).

[xxxviii] Id. s. 2(3).

[xxxix] Id. s. 2(1).

[xl] Law Comm’n, Murder, Manslaughter and Infanticide (Law Com No 304, 2006); Katherine O’Donovan, The Medicalisation of Infanticide, 1984 Crim. L. Rev. 259 (Eng.).

[xli] Homicide Act 1957, supra note 10, s. 2(1A).

[xlii] Willingham & Casey, supra note 1.

[xliii] Three objections merit closer study than space permits here. First, Kahler v. Kansas, 589 U.S. 271, 274–79 (2020), holds that due process requires no particular formulation of the insanity defense, although that holding limits what a defendant may demand of a state rather than what a legislature may enact. Second, partial responsibility doctrines have been criticized as confused hybrids that speak the language of excuse while performing the work of mitigation. See Peter Arenella, The Diminished Capacity and Diminished Responsibility Defenses: Two Children of a Doomed Marriage, 77 Colum. L. Rev. 827 (1977). Third, Massachusetts already permits impairment evidence to defeat premeditation and to negate the knowledge element of malice, see Gould, 380 Mass. at 680–86, although negating an element differs from grading responsibility.

[xliv] Associated Press, Judge Denies Defense Motion Asking Lindsay Clancy Be Found Not Guilty Due to a Lack of Evidence, NBC News (Oct. 2, 2026), https://www.nbcnews.com/news/us-news/judge-denies-defense-motion-asking-lindsay-clancy-found-not-guilty-rcna601086.

[xlv] Nicole Moeder, Lindsay Clancy Due Back in Court as Question of Retrial Remains Unanswered, NBC 10 News (Sept. 28, 2026), https://turnto10.com/news/local/lindsay-clancy-due-back-in-court-as-question-of-retrial-remains-unanswered-sept-29-2026.