Red Riding Hood Plot holes

Super Plot hole:  Gary Oldman becomes convinced that whoever the wolf is must be someone that lives in the town.  He also knows that wolves cannot survive on holy grounds (a major plot point in the movie).  All he needed to do to ascertain the identity of the wolf would be to get everyone into the church before nightfall when the wolf attacks the village.  Whoever doesn’t show up or starts burning is the wolf.  As the expert wolf hunter with quite a bit of experience, you’d think this idea would cross his mind instantly.