What can I do about horrible, violent neighbors?

Almost two years ago, my son was walking our dog on her leash. He was near our house coming home when a neighbors dog ( who is always outside alone with no leash) ran up and starting biting my dogs hind leg. My son tried to stop it and the dog bit him. My dog retaliated and badly injured the other dog. (My dog was chow-lab mix, the other a poodle) I've known my neighbors my whole life and new they would do something to my dog so I sent her away. They called animal control who came to my house for my dog. I told them I would only tell them where she was if they promised not to hurt her. They agreed and said I could pick her up in ten days. They put her to sleep. The officer says that I told her to. The neighbors took me to court and we settled bc it was cheaper than the lawyer.I had a doctors report about my sons bite and a few neighbors saw the incident but animal control refused to talk to any of them. I'm upset but there was nothing I could do. My neighbor was mad bc we didn't pay more. A month later, somebody threw my cat on a grill. He was badly injured, but survived and took over a year to heal. Now he is strictly indoor. Another of my cats has disappeared. The latest was the worse. I took in a cat that had been left by another neighbor when they moved. I already knew the cat and they left her pregnant. She went out one morning at about 4am. I found her at 6am in the road in front of their house. She had been shot in the back. We took her to the vet and neither she or her kittens survived. During this time, our car windows have been shot out and my kids bikes were all stolen. I've lived in the house my whole life (it's already paid off) and I don't want to move. My great grandparents lived in this house, that's how long it has been in my family. My mother has health problems and we cannot afford another house big enough for all of us. The police and animal control say they can't help. I don't know what to do. I have another cat now but she is strictly indoor. I'm scared of what they will do next. I've set up cameras a few times but have not been able to catch them yet. I'm starting to be afraid to even let my kids out of the house. What can I do?