Have you ever wondered why a police department would randomly create a new policy or rule? Why wouldn't they have this policy or rule before? Why make a change now, all of a sudden?
Usually it is because of the above reason. The top brass have a very specific reason for everything, usually political in nature, very rarely having to do with the legitimate reason for policy change, which would be case law, officer safety or citizen safety guidelines being implemented. Consider that next time something like this crosses the news headlines.