If you KNOW it's them... I would straight up confront the dude (verbally)... All this spiteful stuff is really nothing but being a pussy, and if you do anything they will probably figure out it's you and retaliate.

If i KNEW someone shot my dog with a BB gun... I would knock on the door... wait for the husband to come out... and lay one right on his chin.

Later on you can feel free to explain why you did such a thing, but that's optional.