To add to all of this, what kind of person would shoot a kid. Maybe I'm talking ****, as I have never been in a situation like this, but I would think twice about shooting a kid even if he had a gun pointed at me.
If your police officers were more like your firefighters you would be so much more better off. I mean they care about a persons life even at the cost of their own, unlike your police officers who's safety seem to trumps everything else.
I doubt even person mounted cameras are going to help much, as everything can be staged, your problem is the people you hire. You should vet the candidates and not just hire every nutcase who wants the opportunity to kill someone without going to jail or simply gun nuts who want access to weaponry. This goes for your soldiers too, but that's another topic.