Charles is deeply suspicious of the Sheriff, although he can't quite identify the man as a mutant, per se. But he's waiting for the Sheriff to demonstrate something, but instead all he does is sigh with exasperation and tell his deputies Sandburg and Ellison to get on with it.

And then they catch the killer, no one is really telling how they managed but the BAU only confirmed the evidence after the fact, and no one can prove that the Sheriff ever did anything more than hang out at the local bar drinking beer and being lazy.