> the vast majority of violent policing is associated to a relatively small percentage of officers
Isn't the vast majority of crime associated with small areas? People rag on Chicago for having lots of murders, but if you look at http://www.heyjackass.com, you end up finding that most of the shootings occur in only a few neighborhoods.
Similarly, most police officers are not patrolling in a war zone.
Where I would love to see the data is a comparison of officers with their peers. If you're an officer with Chicago's Finest, you probably have a group of peers who patrol the same neighborhoods as you. If you're grabbing your gun five times as often as the other guys on your squad, it's difficult to make the argument that random shit is only happening to you.