Boston's history is checkered with violence and heinous crimes. In 1845, a woman lured into prostitution was murdered at the hands of her jealous lover who used sleepwalking as his defense at trial. A leg was found floating along the Boston Harbor, wrapped in a burlap bag that would later be connected to a woman who was brutally murdered and dismembered by her handyman. In the 1970s, a string of seemingly unconnected murders led to a killer who became known as the Giggler. Christopher Daley explores the tragic events that turned peaceful Boston neighborhoods into disturbing crime scenes.