Dr. Dorothy Lewis is a professor of psychiatry at Yale University and New York's Bellevue Hospital, known for her pioneering research on the cause of violence. Her theories about violence are based on human stories and brain research that focuses on head injuries, brain damage and child abuse. The program follows Dr. Lewis through the murder cases of Arthur Shawcross and Terrance Wainwright. The psychiatrist for the prosecution is Dr. Park Dietz, Dr. Lewis's archrival, who has provided testimony opposing Lewis's views in a number of trials.