"Sam, could you do me a favor?" A seemingly simple request sparks the story that has now become part of America’s true crime hall of fame - the journey of a young lawyer, fresh from the Public Defender’s Office, whose first client in private practice turns out to be the most evil serial killer in our nation's history.

Never-before-heard audio from the interrogation of serial killer John Wayne Gacy threads through this chilling look at his 1970s murder spree.