I just checked up on Vince's Wikipedia page and it states he was convicted for shooting an unarmed man, mostly the same reason Lee was arrested. Now would their be a connection for theese two? maybe they where both there when Lee caught his wife cheating on him.
Vince is a close friend of Lee's he went with Lee to his house too hang out and whatever, and caught Lee's wife alongside Lee. In a blind fury he shot the man dead. However, Lee took this hard, they where both arrested and Vince received full punishment for the crime and Lee for being a accomplice. Note how Lee is only being escorted in a police car and Vince in a van. Lee still feels heavily guilty about this and takes the blame, carrying the guilt with him and leaving his friend out of the tale as to not blame him as much as possible