As the focus starts to shift towards the mystery man who visited the Stevensons just hours before the murders, unique investigative techniques are implemented by law enforcement in an effort to find answers. Forty years later, those tactics are revealed when a cache of never-before-heard recordings are discovered and reveal a puzzle of new information. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.