Sorry buddy, you were wrong.
Zachary Binks, I asked my father about the speed gun thing. Not true. They can speed up behind you and calibrate it with their speedometer. So, be careful, cause there are also cop cars out there now without the sherrif designs on the cars and have a natural paint job to make it look like a normal car. But they are the same type of model that they use for normal patrol cars. Just make sure to look in their front and back windows for lights.