The jury began deliberating Friday in the murder trial of Lindsay Clancy after closing arguments, as the Duxbury mother faces three counts of first-degree murder in the January 2023 strangulation deaths of her children Cora, 5, Dawson, 3, and Callan, 8 months. Clancy has pleaded not guilty. Her lawyers argue she was in the grip of acute postpartum psychosis, bipolar disorder and severe overmedication and therefore could not appreciate the wrongfulness of her actions.