Fun fact: apparently they will reject you for the force if you score too highly on the exam. Don't want the enforcers too smart, I guess.)
This happened once, and the excuse they gave is that smart cops would get bored and quit and they would have wasted money training him/her. I don't know if that holds water, but the courts think so. It's certainly not common practice for local departments to not hire a person that is too smart.
As for the OP, I would trust a random cop (local, state or fed) slightly more than I'd trust a random non-cop.