@cnn: The jury in the trial of Lindsay Clancy, the Massachusetts mother accused of murder after strangling her three young children, has started deliberating following closing arguments. Clancy's defense attorneys argue she was suffering from postpartum psychosis and extreme mental illness and should not be held criminally responsible for the killings. Clancy has pleaded not guilty to three counts of murder and faces life in prison if convicted. CNN's Jean Casarez reports from Plymouth, Massachusetts.