
Poor thing!
And it must be so frustrating for you too Zach Im sure, feeling that you just have to sit idly by,when you feel something could and should be done.
Unfortunately The police will not be able to help you (they will refer you) However it would be worth finding out who your Local 'Community Beat' officer is, especially if your going to keep a diary about this dog (which you should do and photo's if poss.) Have a chat with your Beat Officer ( a good one will have no qualms about 'getting into the community', sadly with work loads they may not see the dog as priority,but use the fact that they do see chatting with locals as useful in networking..so use that to your advantage perhaps)
Good luck, it may feel thankless at the moment but perseverence will pay off!