One of the most famous cases in US history, Charlie Manson and some of his cult members were convicted of the Tate-LaBianca murders in Los Angeles in 1969.
Britannica:
Charles Manson spent much of his youth in juvenile reformatories in West Virginia before heading out to California in 1967. There, by 1968, he had become the leader of the “Family,” a communal religious cult dedicated to studying and implementing his eccentric religious teachings, which were drawn from science fiction as well as the occult and fringe psychology. He preached the coming of an apocalyptic race war that would devastate the United States and leave the Family in a position of dominant power. Manson’s hold over his followers was graphically illustrated in 1968–69, when the Family carried out several murders on Manson’s orders. The most famous victim was actress Sharon Tate, wife of motion-picture director Roman Polanski, who was killed in her Los Angeles home along with three guests. The ensuing trial of Manson and his followers in 1970 attracted national attention.
We are dealing with a political party that is a cult these days.
Open thread.