Philip Markoff was a Boston University medical student engaged to be married when police connected him to a string of armed robberies and one murder, all arranged through Craigslist ads posted by women offering massage and escort services. The film reconstructs the seven days in April 2009 between the killing of Julissa Brisman, a Manhattan model found dead in a room at the Boston Marriott Copley Place Hotel, and Markoff's arrest, drawing on police accounts and interviews with women he robbed at gunpoint after answering their listings. It also lays out what investigators found once they looked past his clean-cut public life: profiles on alternative-lifestyle websites describing interests in bondage and domination that his fiancée and classmates never knew about. The film treats that gap between the two lives as the real subject, using the case files and victim testimony to trace how an engaged, high-achieving student turned into the man the press nicknamed the Craigslist Killer, and how close he came to disappearing before the pattern connecting the robberies to Brisman's murder was even noticed.