He was a part of MK Ultra. He was arrested and released many times, after his 1967 prison release. These were for some rather serious crimes, and he a long rap sheet.
The CIA tested prisoners with lsd. His parole officer was part of the MK Ultra 'project ' and Manson was released from prison on March 21, 1967 and almost immediately began forming his brainwashed cult and was constantly in trouble with the law and released almost immediately, everytime.
He was initially in San Francisco, Haight- Ashbury area and moved his family to The Spahn ranch outside of LA, in the desert, in 1968.
He was a con man, who was a test subject for the CIA. There is a great book about this aspect of The Manson Family and Charles Manson himself. I forget the name and the author. I have been wanting to buy a copy of it. But I forgot to write down the books name and author, opps.
He had massive amounts of lsd. He had successfully brainwashed his followers. That 5'2, little scumbag, had spent most of his life since his teens locked up, but was 32 and used his con artist skills and lsd to brainwash those stupid kids into doing his bidding.
He also helped the establishment, have the myth of hippies being peaceful and harmless destroyed and dealing a huge blow to hippie culture and all that hippie shit of the 60's.
He was a useful scumbag for the government's secret brain washing project and also gave them another gift. The start of the end of hippie culture. Or at least ruining it to a large degree. People began looking at hippies differently after the Tate- Labianco murders; after The Family members and Manson were caught and charged with those heinous murders.
Speed didn't play any part as far as I know.