The C-O-P thing isn't a hint. It's to give credit to a roleclaim. To show that from post one, that's what you are, and you haven't made it up on the fly to adapt to a situation.

As for hints, sure, if the person is innocent you should hint. But if they're guilty, you should claim. Why waste time watching the town bicker about Jack Stupid Townie when you can give them a lead?