Witnesses report that he was in good spirits and had no intention of dying prior to the incident. Add to to this that very conveniently vigilance cameras malfunctioned, guards were told to leave post, and there was no physical way in his cell he could have hanged himself, it becomes apparent what probably happened; some brute got in, snapped his neck, and got away. Since the dude was an scumbag, nobody will miss him enough to do a throughrough investigation (but in any case, we still don't even know who killed kennedy...), but it's a pity because he could have implicated a lot of pedos that would potentially have gone down with him.