In his new memoir "Trejo," the 77-year-old actor revealed he was locked up in Los Angeles County Jail in 1961, where the notorious cult leader was imprisoned and the two would embark on a hypnosis session.
While the "greasy, dirty, scrawny" Manson was too small to protect himself, according to Trejo, he did manage to convince the "Machete" star and his cohorts that he had hypnotic powers that could get make them to feel "high."
"It was like a guided meditation," Trejo wrote, adding that Manson insisted the group would have the sensation of smoking marijuana, then heroin.
"By the time he described it hitting my bloodstream, I felt the warmth flowing through my body," Trejo, who was a teenage heroin addict, recalled. "If that white boy wasn't a career criminal, he could have been a professional hypnotist."
Trejo would eventually turn his life around and become a successful actor in Hollywood, creating his own booming taqueria empire along the way.
Manson, on the other hand, was released in 1967 and immediately began attracting a group of followers in California who would become known as the Manson Family. In 1969, Manson convinced the group to start "Helter Skelter," a brutal murder spree in Los Angeles that killed seven people, including actress Sharon Tate.
Although the court said he never directly ordered the murders, his involvement was enough for him to be convicted of first-degree murder and conspiracy to commit murder in 1971. He died from cardiac arrest and colon cancer while still imprisoned in 2017.