If Lindsay Clancy Were Tried in Illinois: No Soft Landing

Last Reviewed & Updated: August 28, 2026

By: W. Scott Hanken | Former Sangamon County Prosecutor | Springfield Criminal Defense & Violent Crimes Defense Attorney | Voted “Best Attorney” — Illinois Times Best of Springfield & State Journal-Register Reader’s Choice | Springfield, IL | Sangamon County | (217) 544-4057 | hankenlaw.com

Illinois does not recognize temporary insanity or diminished capacity as guilt-phase defenses. Under 720 ILCS 5/6-2, a defendant is legally insane only if, at the time of the offense, a mental disease or defect left them without substantial capacity to appreciate the criminality of their conduct. The defendant must prove that by clear and convincing evidence, the reverse of Massachusetts, where the prosecution bears the burden once the issue is raised.

Bottom Line: If a case like this one were charged in Sangamon County instead of Plymouth County, three things would change immediately: who has to prove what, what mental capacity standard applies, and what verdicts a jury could actually return. Illinois offers a guilty but mentally ill verdict that Massachusetts does not, and it closes off the second degree murder and manslaughter exits that Massachusetts leaves open. That combination makes the insanity finding itself decisive.

A serious mental-health-based defense is one of the hardest things to raise in an Illinois courtroom, and one of the most misunderstood. If you or a family member is facing a case in Sangamon County where a psychiatric diagnosis is part of the picture, call W. Scott Hanken, Attorney at Law at (217) 544-4057 for a free consultation before you say anything else to police or prosecutors.

What Is Lindsay Clancy Charged With, and What Has the Jury Been Asked to Decide?

Lindsay Clancy is on trial in Plymouth County, Massachusetts, charged with three counts of first-degree murder after admittedly strangling her three young children in the basement of the family’s Duxbury home in January 2023. Five-year-old Cora and 3-year-old Dawson were pronounced dead that day; 8-month-old Callan was hospitalized and died several days later. She has pleaded not guilty, and her defense contends she suffered a postpartum psychotic break that left her hearing a voice telling her to kill the children and herself. Prosecutors argue the killings were premeditated, the product of exhaustion and depression rather than a break from reality.

Reports on the exact witness count varied by outlet, but the jury heard more than 70 witnesses over 21 days of testimony, including 10 defense witnesses. For each child, jurors received a separate verdict slip with five options: not guilty, not guilty by reason of lack of criminal responsibility, guilty of first-degree murder, guilty of second-degree murder, or guilty of manslaughter. The specific verdict matters less here than the legal standard the judge instructed the jury to apply, since that standard is fixed regardless of outcome, and it’s where the real story for Illinois readers begins.

What Standard Did the Massachusetts Judge Instruct the Jury to Apply?

Massachusetts calls its version of the insanity defense “lack of criminal responsibility.” The controlling case is Commonwealth v. McHoul, 352 Mass. 544 (1967), which adopted a dual test: a defendant is not criminally responsible if a mental disease or defect left them without substantial capacity either to appreciate the wrongfulness of their conduct or to conform their conduct to the requirements of the law. That “or” matters. A defendant can meet the Massachusetts standard by showing either that she didn’t know right from wrong, or that she couldn’t control herself even if she did.

Just as important, the burden in Massachusetts sits with the prosecution. Once the defense raises the issue, the Commonwealth must prove beyond a reasonable doubt that the defendant was criminally responsible, not the other way around. If the jury isn’t convinced the state met that burden, the result is a finding of not criminally responsible, and the case moves to civil commitment rather than sentencing.

How Does Illinois’s Insanity Defense Differ From the Massachusetts Standard?

Illinois law states the rule this way: “A person is not criminally responsible for conduct if at the time of such conduct, as a result of mental disease or mental defect, he lacks substantial capacity to appreciate the criminality of his conduct.” (720 ILCS 5/6-2(a))

Notice what’s missing. There is no “or conform his conduct to the requirements of the law” in that guilt-phase test. Illinois dropped the volitional prong from the insanity defense, and shifted the burden of proof to the defendant at the higher clear and convincing standard, through a legislative history that is more tangled than it first appears. Public Act 89-404 enacted both changes in 1995, but the Illinois Supreme Court struck down that entire Act in People v. Reedy, 186 Ill. 2d 1 (1999), for violating the state constitution’s single subject rule. A voided act is treated as though it was never passed. The General Assembly reenacted the identical insanity-defense language in Public Act 90-593, and in People v. Ramsey, 192 Ill. 2d 154 (2000), the Illinois Supreme Court held that those reenacted provisions took effect January 1, 1999, six months after the Act’s general effective date. The end result today is the same cognitive-only test and the same clear-and-convincing burden. (720 ILCS 5/3-2(b); 720 ILCS 5/6-2(e))

That’s two structural differences stacked on top of each other. A Massachusetts defendant benefits from a broader legal test and a prosecution-side burden. An Illinois defendant faces a narrower test and carries the burden personally, at the higher clear-and-convincing standard.

What Happened to Illinois’s “Irresistible Impulse” Prong?

Before 1999, Illinois used essentially the same dual test Massachusetts still uses today: appreciate the criminality of the conduct, or conform conduct to the law. Public Act 89-404 first eliminated the second half in 1995, but that entire Act was later declared void ab initio for violating the single subject rule, and the same change was reenacted through Public Act 90-593, effective for the insanity defense on January 1, 1999. The volitional language didn’t disappear from Illinois law entirely, though. As discussed below, it resurfaced as a sentencing mitigation factor rather than a trial defense, which tells you a great deal about how Illinois has chosen to handle these cases: consider the impairment, but only after guilt is decided.

Is There a “Temporary Insanity” Defense in Illinois?

No. Illinois law does not carve out a separate, lesser category called “temporary insanity” as a trial defense. The statute asks a single question: was the defendant, “at the time of such conduct,” unable to appreciate the criminality of what she was doing? (720 ILCS 5/6-2(a)) If the answer is yes, it’s insanity, regardless of whether the underlying condition lasted an hour, a week, or a lifetime. If the answer is no, no amount of emotional distress, sleep deprivation, or diagnosed depression gets you a lesser version of the guilt-phase defense. Interestingly, the phrase “temporary mental illness” does appear in Illinois law, but only in the sentencing mitigation statute discussed below, never in the insanity statute itself. That distinction trips up a lot of people who’ve heard the phrase used loosely.

Does Illinois Recognize “Diminished Capacity” as a Separate Defense?

Not as a guilt-phase defense, though Illinois comes closer to it than most people realize, just in the wrong phase of the case. Diminished capacity, the idea that a defendant’s mental impairment, short of full insanity, can negate the specific intent required for a charge like first-degree murder, was recognized for decades in states like California as a way to avoid conviction outright. Illinois has never adopted that version. A defendant either meets the 720 ILCS 5/6-2 insanity standard or she doesn’t; there’s no in-between finding that reduces the charge itself.

Illinois does account for exactly this kind of impairment at sentencing, and has for longer than most people assume. 730 ILCS 5/5-5-3.1(a)(16), already on the books before Public Act 100-0574 existed, lists as a mitigating factor a mental illness “insufficient to establish the defense of insanity” that “substantially affected” the defendant’s ability to understand her acts “or to conform her conduct to the requirements of law.” That is the Massachusetts volitional prong, word for word, relocated from the guilt phase to the sentencing phase. In Illinois, it can shorten a sentence. It cannot avoid a conviction. Public Act 100-0574 (2018) added a second, narrower factor next to it, 730 ILCS 5/5-5-3.1(a)(17), aimed specifically at postpartum depression and psychosis.

In 37+ years of criminal defense in Sangamon County, I’ve seen how rarely a full insanity defense gets raised, and how much preparation it takes when it does. A genuine insanity defense in Illinois requires forensic psychiatric evaluation, often from more than one expert, months before trial. Judges here don’t take the issue lightly, and neither does the State’s Attorney’s office. Raising it without the clear-and-convincing evidence to back it up can do more harm than good in front of a Sangamon County jury, particularly once you understand what happens if the jury believes you were ill but not insane.

What Is Illinois’s “Guilty But Mentally Ill” Verdict, and Why Doesn’t Massachusetts Have One?

This is the piece of Illinois law with no Massachusetts equivalent, and it’s the biggest practical difference between the two systems. The verdict itself is defined in 720 ILCS 5/6-2(c) and (d): a defendant who was not insane but was suffering from a mental illness at the time of the offense “is not relieved of criminal responsibility… and may be found guilty but mentally ill.” Section 720 ILCS 5/6-4 works alongside it, clarifying that mental illness is not a freestanding affirmative defense but an “alternative plea or finding” available once insanity has been raised. The trial procedure for reaching that special verdict sits in 725 ILCS 5/115-4(j), which requires the defendant to prove the mental illness itself by a preponderance of the evidence, a lower bar than the clear-and-convincing standard insanity requires, but a burden the defendant carries either way.

Here’s the part that catches people off guard: a GBMI finding is a conviction. A defendant found guilty but mentally ill may receive any sentence available for a guilty verdict on the same offense. (730 ILCS 5/5-2-6(a)) The only real difference is that a GBMI defendant is supposed to receive psychiatric treatment during incarceration. She still goes to prison. The Illinois Supreme Court upheld the constitutionality of this scheme in People v. Lantz, 186 Ill. 2d 243 (1999), rejecting arguments that GBMI’s competing burdens of proof denied defendants a fair trial.

This is not a hypothetical outcome. In People v. Gindorf, 159 Ill. App. 3d 647 (1987), a Lake County mother charged with causing her two young children, ages 23 months and 3 months, to overdose on sleeping pills while she was suffering from postpartum depression was found guilty but mentally ill on two counts of murder following a bench trial. She was sentenced to the mandatory term of natural life imprisonment, the same sentence a straight guilty verdict on two murder counts would have carried. The judge who tried her case believed she was genuinely ill. It didn’t matter for sentencing purposes, because Gindorf was tried and sentenced decades before either of Illinois’s postpartum-specific statutes existed. Illinois Governor Pat Quinn later commuted her sentence in May 2009, roughly 23 years after her conviction, reducing it from natural life to 48 years. Under Illinois’s determinate sentencing structure, that made her eligible for release through day-for-day good-conduct credit after having served half the term. That commutation came through executive clemency, not through any statute discussed in this article, and it underscores rather than undercuts the point: absent that discretionary act, GBMI would have kept her in prison for life.

Compare that to a very different Illinois outcome: in 2012 a Cook County judge found Janet Thies-Keogh not guilty by reason of insanity after she suffocated her 8-month-old son during what the court described as a severe postpartum condition. The judge ordered her evaluated by the Illinois Department of Human Services rather than sentencing her to prison, the first step toward the treatment-focused disposition that follows an NGRI finding. Same general fact pattern as Gindorf, opposite result, because one case cleared the higher insanity bar and the other didn’t. That gap, between “mentally ill” and “legally insane” under Illinois’s cognitive-only test, is where these cases are actually won or lost.

What Verdict Options Would an Illinois Jury Actually Have in a Case Like This?

Fewer than the Massachusetts jury got, and this is the least understood difference between the two states. The Clancy jury received five choices per child. An Illinois jury on the same facts would realistically see four, because Illinois builds its homicide offenses differently from the ground up.

Start with first degree murder. Illinois requires only that the defendant intended to kill or do great bodily harm, knew the acts would cause death, or knew they created a strong probability of death or great bodily harm. (720 ILCS 5/9-1(a)(1), (a)(2)) There is no premeditation element anywhere in the Illinois statute.

Illinois does have its own felony murder rule, a third route to first degree murder for a killing that occurs during a separate forcible felony as defined at 720 ILCS 5/2-8. (720 ILCS 5/9-1(a)(3)) The SAFE-T Act narrowed it in 2021, so the death must now be caused by the defendant or another participant in the felony rather than by a third party responding to it. But the more important limit here is judicial. The Illinois Supreme Court has held that the predicate felony must involve conduct committed with a felonious purpose other than the killing itself, and that a forcible felony cannot serve as the predicate where the acts constituting it arise from and are inherent in the act of murder. (People v. Morgan, 197 Ill. 2d 404 (2001)) Two years later the court applied that rule to a case involving an infant: a father who threw his three-month-old son against a dresser could not be convicted of felony murder predicated on aggravated battery of a child, because the act of throwing was both the battery and the killing. (People v. Pelt, 207 Ill. 2d 434 (2003)) A strangulation raises the same problem. Felony murder isn’t the theory in play on facts like these, and it doesn’t need to be — the direct intentional and knowing theories at (a)(1) and (a)(2) already cover them.

Massachusetts requires the Commonwealth to prove malice under one of two theories: deliberately premeditated malice aforethought, or extreme atrocity or cruelty. (G.L. c. 265, § 1) A third theory, felony murder, still appears in the Massachusetts statute, but it no longer stands on its own. In Commonwealth v. Brown, 477 Mass. 805 (2017), the Supreme Judicial Court prospectively held that a murder conviction requires proof of actual malice; felony murder today functions only as an aggravating factor that can elevate an already-proven murder to the first degree, not as an independent path to a conviction. Those two malice-based theories, premeditation and extreme atrocity or cruelty, are exactly what appeared on the Clancy verdict slip.

That difference matters more than almost anything else here. The fight that consumed weeks of the Clancy trial, whether she planned the killings by sending her husband on a longer errand and choosing the basement, goes directly to the degree of the offense in Massachusetts. In Illinois that same evidence would not change first degree murder into something lesser. It would matter to the insanity question and at sentencing, not to the grade of the charge.

Now the piece that surprises even experienced practitioners from other states. Illinois second degree murder is not a residual catch-all for murders that fall short of premeditation. It exists only where the defendant proves, by a preponderance of the evidence, one of exactly two mitigating factors: acting under a sudden and intense passion resulting from serious provocation by the person killed (or by another the defendant meant to kill, if the person killed died negligently or by accident instead), or an unreasonable but actual belief that the killing was legally justified. (720 ILCS 5/9-2(a), (c)) Mental illness is not on that list. Postpartum psychosis is not on that list. Massachusetts, by contrast, defines second degree murder as any murder that does not appear to be in the first degree, a true fallback tier. An Illinois defendant in a Clancy-type case would have no realistic path to second degree murder at all.

Involuntary manslaughter closes off too. Illinois requires reckless acts likely to cause death or great bodily harm. (720 ILCS 5/9-3) An intentional strangulation does not fit recklessness, which is why a Sangamon County judge would be unlikely to instruct on it.

Put together, an Illinois jury on these facts would be choosing among guilty of first degree murder, guilty but mentally ill of first degree murder, not guilty by reason of insanity, and not guilty. There is no compromise middle rung of the kind Massachusetts offered. The practical consequence is severe: with the lesser-degree exits closed, everything rides on the insanity finding, and that is the finding Illinois makes hardest to reach.

Massachusetts vs. Illinois: Key Differences

What If a Sangamon County Defendant Raised Postpartum Psychosis at Trial, Not Just at Sentencing?

Illinois built two separate tools here, added by two different Public Acts, and it’s worth being precise about which one does what, because both carry the same hidden trap. First, 730 ILCS 5/5-5-3.1(a)(17), added by Public Act 100-0574 (2018), lets a defendant present undiagnosed or untreated postpartum depression or psychosis as a mitigating factor at her original sentencing hearing, after conviction. But the statute’s own text limits it to a diagnosis or testimony that “was not used at trial.” If postpartum psychosis was already the centerpiece of a failed insanity defense, as it would be in a Clancy-type case, (a)(17) does not apply at sentencing. The general mental illness factor at (a)(16) still does, since it carries no such restriction, but it is the weaker of the two and does not name postpartum conditions specifically. Second, 735 ILCS 5/2-1401(b-10), added the following year by Public Act 101-0411 (2019), lets a person already convicted of a forcible felony seek modification of her sentence, without disturbing the underlying conviction, if qualified medical evidence of postpartum depression or psychosis was never presented at trial or sentencing, proven by a preponderance of the evidence. That statute carries the identical “never presented at trial or sentencing” limitation, for the same reason. That second tool originally lived at 725 ILCS 5/122-1(a)(3) under the 2018 Act; the 2019 Act relocated it to the Code of Civil Procedure, and the post-conviction petition ground at 725 ILCS 5/122-1(a)(3) is now blank in the compiled statutes.

Neither tool touches the guilt-phase insanity test. A Sangamon County defendant raising postpartum psychosis as a full defense at trial still has to satisfy the same cognitive-only standard under 720 ILCS 5/6-2, proven by clear and convincing evidence, that any other defendant carries. These statutes become relevant only once that guilt-phase fight is over, whether it ends in acquittal, GBMI, or a straight conviction.

What If the Jury Believes a Defendant Was Mentally Ill but Not Legally Insane?

Under Illinois law, this is exactly the scenario 720 ILCS 5/6-2(c) was written for, and it’s the outcome that surprises families the most. If the jury concludes the defendant suffered from a genuine mental illness at the time of the offense, but the illness did not rise to the level of preventing her from appreciating the criminality of her conduct, the result in Illinois is guilty but mentally ill, not an acquittal, and not automatically a reduced sentence. The illness can still be argued as mitigation under the general factor at 730 ILCS 5/5-5-3.1(a)(16); the postpartum-specific factor at (a)(17) is usually unavailable by this point, since the diagnosis was already used to support the failed insanity claim. But as Gindorf illustrates, a Sangamon County Circuit Court jury reaching that same conclusion in a multiple-victim case faces the state’s harshest sentencing exposure regardless of which mitigating factor applies.

What If a Similar Case Involved More Than One Victim?

Illinois law treats multiple-victim murder as one of the most serious sentencing categories on the books. Under 730 ILCS 5/5-8-1(a)(1)(c)(ii), the court shall sentence a defendant to a term of natural life imprisonment if that defendant had attained the age of 18 at the time of the murder and is found guilty of murdering more than one victim. That language is mandatory, not discretionary, confirmed directly against the current Illinois Compiled Statutes. A GBMI verdict does not create an exception to that exposure, and the sentencing mitigation factors discussed above operate within that mandatory framework rather than around it. This is the exact intersection where the Gindorf case sits, and it’s why the guilt-phase insanity fight carries so much weight in a case with more than one victim.

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About the Author: W. Scott Hanken, Attorney at Law
Scott Hanken is a Springfield, Illinois criminal defense attorney with over 37 years of experience, including service as a former Sangamon County prosecutor. He has been voted Best Attorney by the Illinois Times and State Journal-Register, holds an Avvo 10.0 “Superb” rating, and has earned over 270 five-star Google reviews. He serves clients throughout Sangamon County and Central Illinois.

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This article is for general educational purposes only and does not constitute legal advice. Every case is unique — contact an experienced Springfield criminal defense attorney for guidance on your specific situation.