A Massachusetts woman who was known as an advocate for the mental health of emergency workers is being sought by the police after her husband, an officer, was found dead.

Ms. Clancy has pleaded not guilty to murder, citing postpartum psychosis. Two defense witnesses said she spoke lovingly of her children after the killings.

© Pool photo by Josh Reynolds

Ms. Clancy, who is on trial for murder in the deaths of her three children, tried to find treatment for her deteriorating condition, her ex-husband’s mother testified.

© Pool photo by Jonathan Wiggs