Plot Synopsis

Using newly acquired audio recordings of convicted murderer Charles Manson, MANSON SPEAKS: INSIDE THE MIND OF A MADMAN is a two-part special that follows retired LAPD cold case detective Cliff Shepard and researcher Charlie Cook, as they embark on a quest to connect an unsolved cold case murder to Manson and the Manson family. This four-hour, two-night program investigates other mysterious deaths from the same timeframe and reveals new accounts of Manson's violence and influence over others. The special also presents a new theory on Manson's motives that does not align with the "Helter Skelter" theory under which he was prosecuted; brings forth eyewitnesses who are speaking publicly about Manson for the first time; and makes contact with the only convicted Manson Family killer who is currently out of prison and living under a pseudonym.

Cult leader Charles Manson was the mastermind behind the brutal murders of nine people ---- seven occurring over a two-night killing spree in Los Angeles in 1969, including pregnant actress Sharon Tate. Two years later, Manson and many of his followers were found guilty of some of the most vicious murders in California's history. Detective Shepard, who was responsible for catching some of LA's most dangerous serial killers, has been haunted by the Manson murders his entire career. Convinced that Manson's crimes extend beyond the nine murders for which he was convicted, Shepard, alongside Cook, has launched his own investigation to uncover the truth. Key to Shepard's efforts is unparalleled access to 26 hours of never-before-broadcast audio recordings of Manson and confidant-turned-author Marlin Marynick. Marynick recorded his phone calls with Manson over roughly 10 years, and in these conversations, Manson speaks cryptically about Sharon Tate and others. Detective Shepard scours the calls for new evidence as he also investigates two other deaths -- the gruesome murder of a 19-year-old girl and a mysterious suicide -- that he believes may be connected to the Manson Family.

The two-night special, MANSON SPEAKS: INSIDE THE MIND OF A MADMAN, debuted from 9-11pm ET/PT on History Channel on consecutive nights -- Sunday, December 3 and Monday, December 4, 2017 -- two weeks after Manson died on November 19.