Quentin Tarantino had cast most of the roles for his ninth film, 'Once Upon A Time In Hollywood.' But there was one key vacancy open until now, UpRoxx reports. That would be the role of Charles Manson, who isn't the star but plays a key role. Entertainment Weekly confirmed that Australian actor Damon Herriman has nabbed the role. Herriman is best known for his role as Dewey Crowe on FX's 'Justified.'