Prosecution Experts Testify Lindsay Clancy Is Criminally Responsible

Prosecution expert witnesses testified Tuesday in Plymouth Superior Court that Lindsay Clancy remained aware of the illegality of her actions when she strangled her three children in their Duxbury home on Jan. 24, 2023.

Dr. Kirk Heilbrun, a forensic psychologist and professor at Drexel University, told the jury that Clancy was motivated by intent to commit suicide rather than an unmanageable psychotic breakdown.

"She retained an awareness of the illegality of killing people, including killing her children," said Heilbrun. "My clinical opinion is that she was criminally responsible on January 24."

Heilbrun added that Clancy believed her children were better off dying alongside her rather than surviving without their mother. His appearance followed a defense motion for a mistrial on Monday over striking testimony regarding religious beliefs, which Judge William Sullivan denied.

Dr. Gregory Saathoff, an FBI forensic psychiatrist and professor at the University of Virginia School of Medicine, served as the state's final rebuttal witness. He detailed interviews conducted with Clancy in May and June of 2026.

Saathoff recounted Clancy's description of hearing a voice ordering her to harm her children while she prepared food in her kitchen, shortly after speaking to her husband on the phone.

"'This is your last chance, you have to kill your kids and then kill yourself,'" said Saathoff, quoting Clancy's account of the auditory hallucination.

The psychiatrist expressed skepticism regarding Clancy's claims of sudden auditory hallucinations, noting that sudden termination of voices immediately following an act is inconsistent with established psychiatric clinical observations.

"Then just as soon as it started, it stopped, when she had finished killing the children," said Saathoff.

Saathoff highlighted contradictions between Clancy's reported timeline and physical evidence from the crime scene, as well as discrepancies in prior statements provided to her husband, Patrick Clancy, and defense experts.

"What was significant to me is she had not spoken about hearing voices before that," said Saathoff. "That was unusual and also what was very unusual was the fact that the voice stopped with the death or the strangling of her youngest son, Callan."

Saathoff further pointed out the irregularity of the voice ceasing right after the killings occurred.

"Committing the act is not curative of the voice. I’ve not ever seen that," said Saathoff.

The trial established that Clancy strangled 5-year-old Cora, 3-year-old Dawson, and 8-month-old Callan before jumping from a second-story window, leaving her paralyzed. She has pleaded not guilty to three counts of first-degree murder by reason of insanity.

Saathoff emphasized that inconsistency in Clancy's accounts raised significant doubts about the reliability of her narrative regarding the sequence of events.

"In this case the widely divergent reports … raise questions about what she is telling me and how things are happening," said Saathoff. "Certainly that’s a cause for significant concern."

Saathoff will resume his testimony Wednesday morning. Closing arguments in the trial are scheduled to begin Thursday.