What do you do to a neighbor that shot your dog?

My neighbor shot my dog, of course they deny it, but they shot my other neighbors dog the day before. I would of kept my dog up if i knew she was wandering off, but we weren't aware she was even going over there. They shot her then took her to a creek and dumped her in it. She was my kids dog more than mine, and one of my kids helped me get her out of the creek she was lying in. We had to bring her home to bury her instead of letting her rot in a creek. How can a person deal with low lifes like this?