Expert on the case, Michael Butterfield, brings you this compelling deep dive into one of the most chilling and perplexing unsolved murder cases of all time - that of the Zodiac Killer.

The Zodiac Killer conducted a campaign of terror in the late 1960s, killing five victims and taunting investigators through a series of cryptic letters, clues and coded messages sent to local newspapers.

For more than five decades, investigators have searched for the identity of the Zodiac Killer. Hoaxes and forged letters fueled an ongoing media circus while the mystery inspired TV documentaries, feature films, books, websites, podcasts, and even copycat killers.

Michael Butterfield is a writer and researcher who has been investigating the Zodiac case for more than 30 years. He separates fact from fiction and lays out what we know about the crimes, the mysteries and the theories surrounding the case, its legacy in popular culture, and where the investigation stands today.