Based on your neighbors "pressumed" chosen line of work and apparent lack of concern from the police department, I would probably capture their little dog (s) and as someone else suggested and take it to the pound. And, as also suggested, just keep quiet about it. I would do that everytime you could get your hands on a dog in your yard that does not belong there. Either calling the dog officer or bringing it right to the pound. Chances are good, if the current dog dissapears, they will just get another one, but if they continuously dissapear, maybe they will decide to get an indoor pet. Best wishes for you. It is a tough situation.