So a lunatic named Charles Manson gathered a bunch of drifting hippies together and they all ate a TON of LSD. Like several times a daythese people dosed. Making their thought processes muddled to say the least. Manson convinced them he was Jesus essentially, and that the Beatles song "Helter Skelter" was a secret message telling him to start a race war, after which he would lead the surviving white people to an eden in the desert somewhere. The murders were committed by Manson Family members who were instructed to make it look like Black people had committed them in order to set off Manson's desired race war.
Edit: I didn't realize I was in askhistorians, sorry for the cuff. I've actually learned quite a bit about the Manson Family, and have had a face to face conversation with a former member, who was one of the people who robbed a surplus store so they could later kidnap the President. I was part of a theater group that did a lot of research to produce a show about the family