Even if he said, “I killed this guy”...he can’t be prosecuted on this alone. If it happened, it was 47 years ago.
The police could go back to the town he lived in at the time and look for any missing persons reports or bodies discovered, but it’s a long shot.
well they could start an investigation though if the comment was made in a less joking more serious matter and that something actually did occur
murder has no statute of limitations
but self defense from a violent attack is allowed as well
perhaps he should have kept his flipping mouth shut instead of posting it out on facebook