Charles Milles Manson was an American criminal, cult leader and musician who led the Manson Family, a cult based in California, in the late 1960s. Some of the members committed a series of at least nine murders at four locations in July and August 1969. In 1971, Manson was convicted of first-degree murder and conspiracy to commit murder for the deaths of seven people, including the film actress Sharon Tate. The prosecution contended that, while Manson never directly ordered the murders, his ideology constituted an overt act of conspiracy.

The Manson Family was a commune, gang, and cult led by criminal Charles Manson that was active in California in the late 1960s and early 1970s. The group at its peak consisted of approximately 100 followers, who lived an unconventional lifestyle, frequently using psychoactive drugs, including amphetamine and hallucinogens such as LSD. Most were young women from middle-class backgrounds, many of whom were attracted by hippie culture and communal living and then radicalized by Manson's teachings. The group is confirmed to have murdered 9 people, though they potentially killed up to 24.