Prosecutors allege that Clancy strangled the children in the family's home after sending her husband, Patrick, out to pick up a takeout order. After the killings, Clancy cut herself and jumped out a second-floor window but survived the fall, officials said.

Clancy has been receiving psychiatric care since she was taken into custody and is currently being treated at Tewksbury State Hospital, records show.

Clancy is pursuing an insanity defense, acknowledging she killed her children but arguing that her mental state made it impossible for her to conform her behavior to the law.

The 2 p.m. hearing is slated to address issues raised by both the prosecution and defense, records show. Clancy's lawyer, Kevin J. Reddington, said he requested that her appearance at the hearing be waived.

Superior Court Judge William F. Sullivan recently ordered Clancy to submit to a psychiatric examination by medical professionals of the prosecution's choosing, records show.

In asking for Clancy to be held without bail during her October 2023 arraignment, Plymouth Assistant District Attorney Jennifer Sprague said seven medications were detected in blood samples taken from Clancy in the hours after the fatal attacks, which she allegedly perpetrated with exercise bands.

Those details appeared to be aimed at challenging defense assertions that Clancy was overmedicated at the time of the killings. She was being treated for postpartum depression.

Blood tests found three antidepressants, an antipsychotic, two sedatives, and an anticonvulsant medication, Sprague said. There were therapeutic levels of the sedatives and the anticonvulsant in Clancy's system, she said, citing the grand jury testimony of Dr. Margarita Abi Zeid Daou, a psychiatrist hired by prosecutors.

The tests detected the antidepressant trazodone at a level too low to have an effect on Clancy, Sprague said. It also turned up the presence of the antidepressant amitriptyline but couldn't pinpoint how much Clancy had consumed, she said.

Remeron, an antidepressant, and Seroquel, an antipsychotic, were found in Clancy's system at "peak levels," Sprague said, meaning they would have been ingested about two hours before her blood was drawn at 8:15 p.m. She said that was a sign that Clancy consumed those medications after she allegedly strangled her children.

Daou told the grand jury that the most serious consequences for taking this combination of medications at the same dosages would be "cardiac arrest or coma," Sprague said.

Daou "was asked if these medications in these amounts could cause a person to become violent. She said they did not," Sprague said. Daou also testified that the combination of drugs taken by Clancy at the same doses wouldn't cause psychosis, Sprague said.

Four days before the fatal attacks, Clancy conducted an internet search on her cellphone for the phrase, "Can you treat a sociopath," Sprague said.

Clancy also allegedly researched ways to kill on her cellphone before the slayings, according to court records.

"She planned these murders," Sprague said. "She did so with deliberate premeditation and extreme atrocity and cruelty."

At the same hearing, Reddington, said his client has a "very, very, very good defense." He was joined at the arraignment by Paul D. Zeizel, a forensic psychologist who examined Clancy at Brigham and Women's Hospital, where she was treated shortly after the killings.

"She obviously had no reason to kill those three beautiful children, so you have to ask yourself why. Why?" Reddington asked in court. "And when you ask yourself why and you consider all of these factors it's readily apparent, I suggest judge, that this woman was a troubled soul."

Should Clancy be acquitted using the insanity defense, she would be sent to a state psychiatric hospital and come up for periodic evaluation to determine whether she still presented a public safety threat and could be released.

Her trial is scheduled to begin on Jan. 5, 2026, records show.