Having to deal with the ongoing battle between us and predators is bad enough. But when the predator is a neighbors pet it involves all sorts of other issues. I have 7 dogs, two are pitt mixes, and they are all "the best" dogs in the world. I can not even imagine having to shoot a dog. But, as has been said here on BYC before, a neighbors dog in their yard is a pet, in my yard it becomes a predator. We all have the right and responsibility to protect the animals we have take under our care...be they dogs or chickens or anything else. I don't know where you live or if you even could do it if needed but having taken the "right" first step in contacting the authorities if that dog continues to come on your property you may have to resort to more drastic measures.