A mistrial has been declared after a Massachusetts jury deadlocked in the trial of Lindsay Clancy, who killed her three children while in the grip of what she said was postpartum psychosis.

Justice William Sullivan declared the mistrial Friday, after jurors said they were unable to reach a verdict on the seventh day of deliberations.

"It is with a heavy heart that we report that we are unable to come to a unanimous decision and will not be able to," the jury foreperson said in a note on Friday morning. Sullivan gave Clancy's attorney a brief window of time to make a last-ditch plea to the state's highest court to halt the mistrial declaration. After that was rejected, Sullivan made his decision official.

Clancy's weekslong trial drew national attention. Prosecutors portrayed her as an overwhelmed mother who knew what she was doing was wrong, while defense attorneys painted a bleak picture of her deteriorating mental health. Her attorneys said she was not guilty by lack of criminal responsibility, Massachusetts' version of an insanity defense.

Hundreds of women who sympathized with Clancy's postpartum struggle have gathered outside the Plymouth, Mass., courthouse during the trial to raise awareness of the severe mood and anxiety disorders some new mothers face.

Clancy admitted to killing her three children, Cora, 5; Dawson, 3; and Callan, 8 months; but said she did it during a psychotic episode. She said she heard a man's voice telling her to kill herself and the children on the day she killed them.

Prosecutors said she arranged to send her husband out of the family home in Duxbury, Mass., on Jan. 24, 2023, so she would have time to strangle the children with exercise bands in the basement and attempt to take her own life. Assistant District Attorney Shanan Buckingham said during trial that Clancy "acted intentionally, rationally and swiftly to accomplish a very specific goal: to kill."

"This is not a public debate about women's mental health and how the medical system treats women," Buckingham told jurors. "This case is about this defendant, Lindsay Clancy."

The trial included testimony from medical professionals, family, and Clancy's ex-husband, Patrick Clancy, who returned home on the night of Jan. 24 to find blood in the couple's bedroom and his then-wife injured in the backyard from jumping out the second-story window. A 911 call, played in court but not released publicly, captured him finding their children in the basement.

Clancy was severely injured in the fall and is now paralyzed from the waist down.

Much of the trial focused on Clancy's attempts to manage her mental health in the months before the killings. According to testimony at trial, she began experiencing anxiety about returning to work as a labor and delivery nurse after the birth of her youngest child in May 2022. She was prescribed a range of medications for depression and insomnia as her condition worsened. She also went to inpatient treatment and called a suicide hotline.

"??This is a young woman that, with her husband, tried very hard to get the help she needed," Clancy's attorney Kevin Reddington told jurors.

Patrick Clancy has asked the public to forgive his ex-wife, saying the woman portrayed in media reports isn't the person he knew. "The real Lindsay was generously loving and caring towards everyone-me, our kids, family, friends, and her patients," he said in a statement released days after the killings. "All I wish for her now is that she can somehow find peace."

About 1 in 8 women experience postpartum depression, according to the Centers for Disease Control and Prevention. Postpartum psychosis, characterized by losing touch with reality and experiencing paranoia, delusions or hallucinations, is far rarer.

Help is available: Reach the 988 Suicide & Crisis Lifeline (formerly known as the National Suicide Prevention Lifeline) by dialing or texting 988.