[John H K]

If *I* see a white van leaving the scene of a shooting, You can damn well better believe I am going to chase it, Honk, call 911 and harrass it, drawing as much attention as I can.

Define "harrass?"

And how do you tell "leaving the scene" from someone simply driving to their destination?

[SarahW]

Depends, whatever I feel is justified at the time.
Maybe just hog the road if I'm in front, maybe follow too closely if I am behind. FWIW any white van that is aware of a shooting needs to stop. Stop and let the police talk to them. Otherwise, they are asking for it, as far as I am concerned.

You can tell they are leaving the scene if you know there is a scene. If I see or hear hear the shot and see the van pull out in a hurry, I'm following. So sorry that frightens you. It's going to happen. And I'm just a mild mannered housewife...

I know some folks that would shoot out the tires.