Two women, two decades apart, killed their own children while trapped in the same devastating illness. Their cases ask the same hard question: was it a crime, or was it a sickness?

Some stories are almost too painful to read. This is one of them. But it is also a story that every parent, every juror, and every reader should understand, because it touches something most people never expect to face: a mother so sick that she harms the children she loves most.

In 2023, Lindsay Clancy, a former labor and delivery nurse in Massachusetts, strangled her three young children, Cora, Dawson, and Callan, then jumped from a second-story window in an attempt to end her own life. More than twenty years earlier, in 2001, Andrea Yates, a Houston mother of five, drowned her children, Noah, John, Paul, Luke, and Mary, in the family bathtub. Both women say they were suffering from postpartum psychosis. Both cases forced juries, and the public, to ask whether a mother in the grip of severe mental illness can be held criminally responsible for what she did.

This piece looks at both cases side by side. It explains what postpartum psychosis is, how the insanity defense works, and why these two cases, separated by more than twenty years, still raise the same painful and unresolved questions.

Two Cases, One Devastating Pattern

Postpartum psychosis is rare. It affects roughly one to two mothers out of every 1,000 births. It is far more severe than the “baby blues” or even postpartum depression. Doctors describe it as a mental health emergency. A woman in psychosis can lose touch with reality. She may see or hear things that aren’t there, believe things that are not true, or become convinced that something terrible will happen unless she acts. Symptoms usually appear within days of giving birth, though they can develop up to six weeks or later.

Andrea Yates had a documented history of severe mental illness before the killings. She had been hospitalized more than once, had attempted suicide twice, and had been treated for postpartum depression after earlier births. Her attorneys said that by the morning of June 20, 2001, she believed Satan was inside her and that killing her children was the only way to save their souls from hell. Police who arrived at her home said she was calm and told them plainly, “I killed my kids.”

Lindsay Clancy’s case shares striking similarities. She too had worked in a medical setting, caring for new mothers and infants as a labor and delivery nurse. Her defense attorney says she had been diagnosed with postpartum depression that spiraled into psychosis, and that despite repeated visits to doctors and psychiatric nurse practitioners, her worsening symptoms went untreated. Text messages shown at trial reveal Clancy telling her own mother, three months before the killings, “I’m really sick. Something is wrong.” Prosecutors don’t dispute that Clancy killed her children. They argue instead that she understood what she was doing and should be held responsible.

I’ve worked with people who have killed their families, and I can tell you from my experience that none of them did it out of malice.

• One individual killed his five children and prayed for the day he would die so that he could be appropriately punished for it. He was in the throes of a stress-induced psychosis when he did the killing.
• I believe another man killed his three children and his wife after an incredibly long and highly stressful experience.
• A third man killed his children and his wife. One child managed to escape before he set the house on fire. He, too, wanted to be punished for what he had done, but he was also psychotic at the time.
• Another man killed his sister and two nieces, believing that they were using witchcraft on him to cause extreme pain in his back and legs. It was later discovered that he had arthritis.
• A woman beat her toddler to death with a hammer because she thought the child was possessed.

I never met anyone who killed their children with a clear mind, and all of them wanted to save their children in some way by killing them.

Both these women had no criminal history. Both were, by all accounts, devoted mothers before illness took hold. And in both cases, family members had raised concerns about their mental state in the weeks or months before the killings, concerns that either went unheeded or were treated with medication that didn’t work.

The Insanity Defense: A Hard Case to Prove

Winning a not guilty by reason of insanity (NGRI) verdict is far harder than most people realize. Across all criminal trials, the insanity defense succeeds in less than one out of every thousand cases. Even in cases involving the killing of a child by a parent, where the illness argument is often strongest, success rates climb only to somewhere between 15 and 27 percent, depending on the study.

Most states use a legal test called the M’Naghten Rule, which comes from an English court case in 1843. Under this rule, a defendant must prove that a mental illness left her unable to understand the nature of her actions, or unable to understand that what she was doing was wrong. It is not enough to show that someone was depressed, overwhelmed, or even psychotic.

The defense has to show that the illness broke her connection to reality so completely that she did not know right from wrong at that exact moment. This is one of those moments that attorneys use.

I’ve heard it said that one attorney asked a jury whether the person had to be psychotic when they pulled the trigger, or whether they were not psychotic before they pulled the trigger. If so, were they responsible for their actions? It seems to be a game of words where we can prove neither case: intact before the pull, psychotic when they pulled the trigger of the gun. Clearly, in my opinion, anybody who is actively psychotic and delusional in their belief about their children doesn’t know that what they are doing is wrong. In fact, they believe it is the right thing to do.

This is why Andrea Yates’s first trial, in 2002, ended in a conviction rather than an acquittal. A jury found her guilty of capital murder, though it rejected the death penalty and sentenced her to life in prison. That verdict was later thrown out on appeal after it came out that a prosecution witness, a psychiatrist named Dr. Park Dietz, had given false testimony during the trial. Dietz said she followed the example on a TV segment of Law and Order where the mother murdered her children. No such segment ever aired.

At her second trial in 2006, a different jury reached a different conclusion. Forensic psychiatrist Phillip Resnick testified that Yates suffered from both psychosis and schizoaffective disorder at the time of the killings. After deliberating for about 13 hours, the jury found her not guilty by reason of insanity. The jury foreman told reporters afterward, “It was very clear to us all that she did have psychosis, before, during, and after.” Yates was committed to a state mental hospital, where she remains today.

Lindsay Clancy’s case, still being heard in a Massachusetts courtroom as of this writing, follows a similar legal path but has not yet reached a verdict. Her defense argues that medical providers failed her, that she was overmedicated, and that she was in a state of psychosis when she killed her children. Prosecutors counter that “people with mental illness commit crimes every day and are responsible for them.” What the prosecutor here fails to recognize is that there is a distinct difference between types of mental illness and the psychosis that may drive someone to murder. Legal experts note that Massachusetts prosecutors have successfully argued against an insanity defense in a similar case before. I believe this is an egregious error.

Less than a month before the Clancy killings, the same prosecutor’s office convicted another mother, Latarsha Sanders, of first-degree murder, despite expert testimony that she was in a severe psychotic state when she killed two of her sons. That earlier case shows how unpredictable juries can be, even when the medical evidence looks similar from one case to the next.

One reason insanity verdicts are so rare is that jurors often struggle with what happens after an acquittal. Contrary to popular belief, a defendant found not guilty by reason of insanity does not simply go free. She is committed to a locked psychiatric facility, sometimes for longer than she would have served in prison, and she can only be released if one or two psychiatrists convince a judge later that she is no longer a danger to herself or others. Legal experts say some jurors choose a guilty verdict anyway, out of fear or uncertainty about what will happen to a defendant found not criminally responsible.

What These Cases Mean for the Rest of Us

Whatever a jury eventually decides in the Clancy case, both of these stories have already done something important. They have forced a national conversation about a form of mental illness that most people know almost nothing about until it touches their own family.

Doctors who study postpartum psychosis say the Yates case, more than twenty years ago, changed how the medical and legal world talks about maternal mental health. Mental health advocates hope the Clancy trial will do something similar today, especially by exposing how often warning signs are missed by the very doctors and nurses trained to catch them.

Women who have survived postpartum psychosis themselves say the constant news coverage of the Clancy trial has been hard to watch, because it reminds them how close they came to a similar tragedy, and how much luck, alongside proper treatment, played a role in their own survival.

Both Andrea Yates and Lindsay Clancy loved their children. According to the people who knew them, both women were caring, careful mothers before illness took hold of their minds. Whether the law calls what happened to their children a crime, a tragedy, or both, these cases remind us that severe mental illness after childbirth is real; it can strike without warning, and it can turn a loving mother into a danger to the people she would otherwise protect with her life.

I know of a woman who, after her first child was born, told her husband, “I’m afraid I’m going to hurt the baby.” She was suffering from postpartum depression, and fortunately her pediatrician stepped in and helped the couple with their child.

If there is a lesson buried in this heartbreak, it may be this: warning signs deserve to be taken seriously, and mothers who say something is wrong deserve to be heard the first time, not after it is too late.

If you or someone you know is struggling after childbirth, help is available through the National Maternal Mental Health Hotline at 1–833–943–5746, and the 988 Suicide and Crisis Lifeline.