My impression is that this is the kind of thing you only see in the movies or among criminal perps. This being a regular guy, I have my doubts. I'm inclined to think that he saw a sudden movement inside the SUV suggesting that a weapon was being readied for use, whereupon he reached for his holstered gun and opened fire. While I think it was a bad idea for him to talk to a bunch of black teenagers who were strangers to him about the noise they were making, simply because of the risk (1) that they were criminals and (2) of escalation, it's not a crime to act in self-defense. Nonetheless, I think there's a chance he may go down for negligent homicide.
No argument from me ZF, but let me ask you something. Were you his legal representative, how would you be able to prove self defense? Sure, he may have seen a sudden movement that made him assume incorrectly, but is that a cogent defense? With the lack of a weapon, and his exit from the scene without reporting the incident to the authorities, I really wouldn’t want to be him. I honestly do not see any way he’d get away with this, and that is without the media attention this case is getting. This is a man in serious need of Alladin’s genie, and even then it may not be sufficient.