The Commune (lost Manson family-inspired film; 1970)
From The Lost Media Wiki
The Commune was a 1970 film directed by Monroe Beehler based on the crimes of the Manson family. Released just 7-months after the Tate–LaBianca murders, the film holds the title of being quite possibly the first film based on the crimes. Very little is known about the film, other than it apparently had its premiere at the Eros Theatre (now New Beverly Cinema) on March 11, 1970. The film later played at the Nob Hill Theatre in San Francisco.