The Torso Murders were the work of what police think was one serial killer operating in Cleveland between 1934 and 1938. The official count of victims is twelve, but there could have been as many as twenty, and many of the twelve victims were never identified.
The murders had started the year before Eliot Ness became Cleveland's safety director - putting him in charge of the police and fire departments, but then continued on and then stopped, with the crime still unofficially solved.
Though rights of the accused would not be really frequently observed in the 1930s, Ness did something in response to the murders that really raised eyebrows even during that time. He had an entire shantytown in Cleveland burned to the ground then arrested everybody there for being homeless. No suspect was found among the shantytown residents.
It's a very light hearted presentation considering the grisly topic, but the episode does leave the viewer with a couple of suspects, some theories, and the name of one person who did in depth research on the subject - true crime author James Badal.
There is one tie in with The Untouchables TV show. In one episode, the Germans are shown to know who Ness is in the 1930s. They did, but not because of his work at the FBI. Instead they knew of him because of the unsolved state of the Torso Murders.