EDITOR’S NOTE: This article contains graphic descriptions of child murder, suicidal ideation, and an attempt to die by suicide.

Opening statements are set to begin Monday in the triple-murder trial of Lindsay Clancy, the Massachusetts mother who has argued she is not criminally responsible for fatally strangling her three young children.

Clancy, a 35-year-old former labor and delivery nurse at a hospital in Boston, has pleaded not guilty to three counts of murder for the killings of her children Cora, 5; Dawson, 3; and 8-month-old Callan.

The opening statements mark the start of Clancy’s trial in a case that will explore the controversial “insanity defense” and the severity of postpartum mental illness.

The core facts of the killings are not in dispute: On January 24, 2023, Clancy fatally strangled her three children in the basement of their Duxbury home using exercise resistance bands. She then cut her wrists and neck and jumped from a second-story window in a suicide attempt, leaving her partially paralyzed.