It's a good point I hadn't considered.

all the same I have to imagine that there are more than 15% of officers who are going to be making some arrests. It's still probably a good place to start sifting through the data. I know that in my city there are a small number of officers that have repeatedly been sued for using excessive force, I wouldn't be surprised if these same aggressive assholes charged people for resisting arrest more than their fellow officers.

The guy who shot a 12 year old girl with a bean bag round is the same guy who kicked in the ribs of a non-threatening mentally ill guy and is probably the same guy that lets situations get out of hand so he can beat some ass a lay a resisting arrest charge (Officer Chris Humphrys).

The data might say something different but I'd be surprised if there isn't a correlation with cops who use excessive force who also charge people with resisting arrest more often because these are the kinds of cops that aren't good at controlling a situation with anything other than physical force.