Agree that warning shots are not a good idea, but the shotspotter system in the area adds another legal dimension. A lawyer would argue that when the second group of gang bangers joined in, it escalated the situation and by activating the gunshot tracker system, he was signaling to the cops for help in the fastest way possible (tracking system + gun shot = cops enroute NOW). The argument could be made that he was not intending harm, only trying to instill a sense of urgency in law enforcement.
Anyhoo, devils advocate time over
. Gotta agree again with the no warning shots. There where better options available.