In a trial that has become a battle of the experts, prosecutors have called two witnesses who say Lindsay Clancy, the Massachusetts mother accused of killing her three children in January 2023, knew exactly what she was doing. The jury is expected to begin deliberations on Friday, and the case hinges on whether Clancy was suffering from postpartum psychosis at the time of the killings.

Forensic psychologist Kirk Heilbrun, hired by prosecutors, testified that Clancy was "criminally responsible" for the deaths of her children, 8-month-old Callan, 3-year-old Dawson, and 5-year-old Cora. "She retained an awareness of the illegality of killing others, including her children," Heilbrun said, adding that her "moral awareness" was influenced by her desire not to leave her children behind if she died. He also said each step she took, including taking the children to the basement, was a decision, painting a picture of premeditation.

But under cross-examination, Heilbrun admitted to earning roughly $54,000 for 180 hours of work on the case, with more likely to come, and that he had no experience with postpartum mental health conditions. His testimony was so contentious that at one point, a recess was called after heated exchanges with Clancy's attorney, Kevin Reddington, who accused Heilbrun of not reading her medical reports. Reddington also requested a mistrial after Heilbrun mentioned Clancy's Catholic faith, which the judge called "an absolutely inappropriate area of testimony" and instructed the jury to disregard.

Prosecutors then called forensic psychiatrist Gregory Saathoff, affiliated with the FBI and University of Virginia, who noted it was unusual that Clancy hadn't reported hearing voices before the killings and that the voices stopped afterward. He also found inconsistencies in her account. Saathoff, unlike Heilbrun, claimed he wasn't paid for his testimony and had treated women who killed their children.

The defense, however, has presented its own experts who concluded Clancy was "clearly psychotic" and not in control of her actions. Dr Phillip Resnick, a forensic psychiatrist and filicide expert, testified that Clancy was "like a puppet and someone else was pulling the strings." Another defense witness, psychologist Paul Zeizel, said Clancy "had no appreciation for the wrongfulness of her act."

Clancy admitted herself to McLean psychiatric hospital weeks before the murders, and it's undisputed that she strangled her children before jumping from a second-floor window, leaving her paralyzed. The trial, which has lasted over a month, is nearing its end, with closing arguments expected Thursday and deliberations to start Friday. Judge William Sullivan has urged jurors to keep an open mind until they've heard all the evidence, the law, and the closing arguments - because, as he reminded them, "You haven't heard all of it, right?"