Neigborhood watch has no legal authority beyond that of ANY citizen. If while you are simply walking home from the store, someone comes out of a house,, and demands to know your name, whats your business, etc,,,
You care free to ignore them, and need not speak a word to them. If they try to stop you,, or they point a gun at you,,, You may exercise the right of self defense. Including punching them in the head and trying to gain control of the gun.
Too bad the kid lost. Sounds like he was in a desperate state when Zimm misunderstood his role as an observer and reporter.
What was the immediate need for Zimm to exit and contact the kid? He knew cops were on the way,, he could have just maintained observation. Now he’s murdered a regular nice kid.
In the same way, if I see someone walking down the sidewalk in front of my house, what's to stop me from walking out on my property and engaging them? If I ask questions that antagonize him, is he allowed to assault me?