Charles Manson may have passed away behind bars at age 83, but his murderous legacy will live on for centuries.

In REELZ’s Charles Manson: The Final Words episode, investigators and friends of the killer’s victims speak of the heartbreaking crimes and the psychotic ideals that led Manson and his “family” to commit them.

“Nothing could have been more horrendous than what happened that night to innocent people who didn’t even know their murderer and the reasons that this maniac orchestrated this whole thing were just looney-tunes!” a deceased victim’s girlfriend, Sharmagne Leland-St. John says in the clip.

While Manson spent the last forty-seven years of his life locked up in a maximum-security jail, he denied his crimes until the very end.

“This is not what I wanted to be. It doesn’t matter what I wanted,” he is hear saying in a recorded phone call.

The convicted killer claimed he was misjudged, adding that Helter Skelter was a myth and the truth behind the murders remains untold.

“I’ve been deep in thought in solitary confinement for almost 40 years, thinking ‘what the hell does this all mean? How does that fit? Where does that work?’ And the stuff that I’ve come up with, man, it’s just unbelievable,” Manson says during the call. “It’s totally unbelievable.”

Charles Manson: The Final Words Premieres Sunday, December 3 at 9 ET/ 8 PT on REELZ.