The film that I have never been able to identify is an old drive in classic from the KENTUCKY FRIED MOVIE / LAST HOUSE ON THE LEFT era. My pal Heidi’s dad used to take us to all sorts of adult (not porn but way too scary) stuff as kids. The film was about a man in prison who made a deal with the voodoo inmate. He was a black man kind of like YAPHET KOTTO. Anyhoo, the spell was cast using a human liver. I did see most of the remaining film peeking through two fingers. It was definitely a ‘60/’70s grainy film set in a prison.
UPDATE: NAME THAT TRAUMA SOLVED! Props to Kahotep for solving it with PSYCHIC KILLER.