This is by no means the official word, but when I used to live in Florida, the law was that you could have a scanner in your vehicle if you were a licensed HAM radio operator, emergency worker, or you had a special letter authorizing you to have one in your vehicle. It may be the same here. I don’t really pay attention since I’m a VFF and EMT and have enough scanners to qualify as a police department emergency dispatch center. Please remember that no matter what your “title” is, it is illegal to use a police scanner to aid you in committing a crime (not to mention the crime is illegal too).