A forensic psychologist testified Monday that Lindsay Clancy was criminally responsible for the deaths of her three young children, stating that she was aware of the illegality and moral wrongfulness of her actions when she strangled them.

Dr. Kirk Heilbrun, a prosecution expert, told the jury that he believes Clancy, 36, was suffering from bipolar disorder and sleep problems, not psychosis, during the incident on January 24, 2023. Clancy has pleaded not guilty by reason of insanity, citing postpartum psychosis, and is seeking commitment to a mental health facility.

Clancy is accused of strangling her children—Cora, 5, Dawson, 3, and 8-month-old Callan—at their home in Duxbury, Massachusetts. She then allegedly attempted to end her own life, which left her paralyzed.

Heilbrun, who interviewed Clancy in April and has spent 180 hours on the case, stated that while depression and hopelessness influenced her decision, she retained control over the timing, location, and method of the killings. "Although this depression and hopelessness influenced her decision, she retained control over when, where and how she carried it out," he testified.

The psychologist presented several reasons for his belief that Clancy was not psychotic. He noted that Clancy's statement of being "horrified" upon waking in the hospital suggests an awareness of what had occurred. Heilbrun also pointed to inconsistencies in Clancy's accounts of a voice she claimed instructed her, noting that her recollection of the voice's specific directives changed over time.

Heilbrun further suggested that it would be unusual for someone to have a phone call with their husband, Patrick Clancy, in the midst of a psychotic episode, as she did when he called to pick up medicine for their children. Instead, Heilbrun proposed that Clancy may have experienced peritraumatic dissociation, a state where an individual feels detached from reality during a traumatic event. This, he explained, can mimic psychotic symptoms but is rooted in the overwhelming nature of the circumstances.

The psychologist detailed several decisions Clancy made during the 18-minute period in which the killings are believed to have occurred. These included selecting the location, the children to be killed, the order of the killings, the method of strangulation using exercise bands, and her own suicide attempt.

Heilbrun described Clancy's actions as fitting the definition of altruistic filicide, which is the killing of one's children out of a misguided belief that it is for their own good. Evidence for this, he stated, includes Clancy's reported last words to her children: "Go to God, baby," which suggested a belief that she and her children would be together in heaven.

During cross-examination, defense attorney Kevin Reddington asked the judge for a mistrial after Heilbrun testified that he asked Clancy if she knew suicide was considered a "mortal sin." The judge rejected the mistrial request but struck the comment from the record.

If you or someone you know needs help, you can contact the 988 Suicide & Crisis Lifeline by calling or texting 988, or by visiting 988lifeline.org.