The long-awaited murder trial of Lindsay Clancy, the Massachusetts mother accused of killing her three young children, is set to begin with opening statements and the testimony of her ex-husband as the prosecution’s first witness.

Clancy, 35, of Duxbury, faces charges of first-degree murder in the January 24, 2023, deaths of her children — Cora, 5; Dawson, 3; and 8-month-old Callan. Prosecutors allege she strangled the children with exercise bands while her husband was briefly out of the house getting takeout, then jumped from a second-story window in an apparent suicide attempt that left her with serious injuries. She has pleaded not guilty.

Jury selection concluded in Plymouth Superior Court, and opening statements are scheduled to begin. Patrick Clancy, the children’s father and Lindsay’s ex-husband, is expected to be the first witness called by the prosecution. He was the one who returned home, discovered the children’s bodies, and made the frantic 911 call that night.

A judge recently ruled that the audio of Patrick Clancy’s 911 call and autopsy photographs of the children will be impounded, meaning they will not be publicly disseminated by the media, though the jury will hear and see the evidence. Patrick Clancy has publicly stated that he forgives his former wife and has indicated he may also testify for the defense.

The defense is expected to argue that Clancy was in the grip of severe postpartum mental illness, including possible postpartum psychosis, and that she was failed by the medical system after seeking help multiple times. She was prescribed numerous medications in the months leading up to the tragedy. Prosecutors maintain the killings were deliberate.

The case has drawn intense national attention since the 2023 tragedy. Clancy, a former labor and delivery nurse, has remained hospitalized or under medical care for much of the time since the incident due to her injuries. The trial is expected to last several weeks and will feature extensive testimony from medical experts, family members, and investigators.

Sources

• Court TV, NBC Boston, CBS Boston,