How did the same actor get cast as Charles Manson in both Once Upon a Time in Hollywood and Mindhunter? Australian performer Damon Herriman portrays the infamous American criminal in Quentin Tarantino’s latest film and in season 2 of Netflix’s acclaimed crime series about the FBI's relationship with serial killers. Previously, Herriman was best known as Dewey Crowe from the FX series Justified.

In 1968, Manson pursued a music career in Los Angeles. He and several women lived in the Hollywood home of The Beach Boys’ Dennis Wilson, who introduced the singer-songwriter to producer Terry Melcher. One year later, Manson relocated to Spahn Movie Ranch, where he became known as a spiritual guru, and allegedly prepared for a race war known as “Helter Skelter.” On August 9, 1969, four Manson Family members drove to Melcher’s former Cielo Drive residence - owned then by filmmaker Roman Polanski and actress Sharon Tate - and killed Sharon Tate, along with four other people.

Related: Mindhunter Cast & Character Guide (& How They Looked In Real Life)

On August 28, 2018, Herriman was officially cast as Manson for Once Upon a Time in Hollywood. Herriman told THR that his former Justified co-star Timothy Olyphant and actor Nicholas Hammond had kindly "put in a word" with Tarantino about the role, as they had already joined the Once Upon a Time in Hollywood cast. Tarantino was reportedly a Justified fan, and so Herriman received an audition. Then, on August 30, Herriman joined Mindhunter as Manson. He'd previously worked with Mindhunter actress Anna Torv, though she wasn't responsible for Herriman's casting. After filming the Netflix series, Herriman began production for Once Upon a Time in Hollywood. Herriman told IndieWire that Tarantino said little about Mindhunter:

“He knew that I’d done it. It would have been weird to keep that a secret… But it didn’t come up much. He said at one point while we were shooting, ‘You’ve done Fincher’s thing already?’ I was like, ‘Yeah, it was a couple weeks ago.’ He said, ‘Cool, how’d that go?’ I said, ‘Great.’ He didn’t ask about any of it other than that. He certainly didn’t say he wanted me to do something different.”

Charles Manson waving in Once Upon a Time in Hollywood

As for Herriman’s acting approach, the two projects called for separate character depictions. In Once Upon a Time in Hollywood, Manson appears just once when he visits Cielo Drive, months before the Tate murders, looking for Melcher. This version of Manson is soft-spoken, clean-shaven, and friendly on the surface, but he still makes Tate feel uncomfortable with his presence alone. For Mindhunter season 2, Herriman portrays Manson in the fourth episode, as special agents from the FBI’s Behavioral Science Unit interview the convict at a California prison. The sequence takes place during the early ‘80s, over a decade after the Cielo Drive murders. To match Manson's look, Herriman received six hours of prosthetic make-up work prior to shooting (via Rotten Tomatoes).

In Mindhunter, Bill Tench (Holt McCallany) and Holden Ford (Jonathan Groff) question Manson about his motivations, allowing for Herriman to fully immerse himself into the role by capturing Manson’s physical mannerisms, vocal intonations, and bizarre conversational techniques. Based on Herriman's research, he came to the conclusion that Manson "would kind of up the crazy elements if the interviewer was treating him like he was crazy" - a concept that's evident in his Mindhunter performance. Despite Herriman’s minor role in Once Upon a Time in Hollywood, he stated to CBS: “The time on the set was the most fun I’ve ever had on any set. You turn up to a Quentin Tarantino set and it doesn’t feel like any other set. There’s 60s music playing and it was really chill.”

In Mindhunter, the narrative tone is much darker than Once Upon a Time in Hollywood, as Herriman's chilling Manson sequence takes place during an investigation into the Atlanta Child Murders of 1979-1981. The character dialogue underlines the season's major themes about doubt, and provides insight about Manson's psychological effect on authoritative figures. The Mindhunter FBI agents use evidence and psychology to establish a logical narrative, but they still have much to learn about serial killer behavioral analysis, and certainly about Charles Manson's true motivations.

More: What To Expect From Mindhunter Season 3