This is what i think happened.
Dip shit starts stalking young bro (for whatever reason)
Young bro obviously notices he's being stalked .
Young bro turns and confronts dip shit.
Dip shit is not ready for this and reacts aggressive.
Young bro promptly whoops dip shits ass with a quick 1,2 dropping dip shit and then runs off.
Punch drunk dip shit pulls his gun and shoots young bro in the back.
Moral of the story,
Two wrongs do not make a right and unfortunately a young bro lost his life.
If this is the case it's manslaughter at the most. Especially if dip shit has assault wounds.
But we just don't know because dip shit is not talking. It will all come out eventually ,we can be pretty confident of that.