Lawrence Phillips and OJ.
Phillips contributed to the end of Steve Young's career, and later tried to run over children in his car after getting mad about a flag football game. Sorry, sorry excuse for a man.
The damage from the O.J. trade led to the hiring of Walsh, so that was somewhat redeeming in a not-really-still-don't-like-him kinda way. He also brutally killed people, though, and threatened others. Glad he's in jail.
Uninteresting footnote: I was on a church trip to SF in the summer of '94, and in Candlestick park the day OJ was on the freeway( watching the Cubs and Giants play, if I recall. Anybody remember Kurt Manwaring?) Anyway, people were getting the pictures taken with the plaque of OJ, because nobody believed that "the guy from the Naked Gun movies" could kill people.