Legal Question in Traffic Law in Maryland

Unless the specific department had a regulation that prohibited the practice, probably not. The issue is whether the equipment was working properly and whether the person using it was qualified.

You may be well served to go to Court on this case, because now it seems like they need two officers at trial to prove you guilty. It would be inadmissible hearsay for the officer who made the traffic stop to testify that the other officer radioed him and said you were speeding.