This guy has stated his intentions. Leaving the truck there is either a distraction technique or preparation for a secondary attack.
I'm surprised he hasn't used a secondary on responding units at a scene.
This is going to get worse before it gets better.
Someone brought that up at a shooting I was involved in. I said he should have stopped. They said "what about Garner v. Tennessee."? I told them, " his name ain't Garner and we ain't in Tennessee!"