A guy got caught around here a few years back for the same thing. He was a real dumbass, though. I can't remember what it was that got him caught, though....whether it was the 3" reflective 'mailbox' type stickers on the car or the fact that he put 'POLICE' on one side and 'SHERIFF' on the other and rode around the county like that.
In Georgia, look at the tag. It should have Gov't on it for all levels of LEO.
Also call *GSP to get in touch with the state police for instructions or dial 911.