I realize you're upset and that this has been very traumatic for you. But you need to stop, cool down and think before you go knocking on doors and accusing someone's dog of killing your birds. The answer you're going to get is, "Oh no. I couldn't have been my FiFi. She'd never hurt a flea! And she NEVER leaves the yard!" All you have right now is a he-said, she-said situation. Until you have proof, there's really nothing you can do. You can file a complaint and tell the officer "I THINK it was FiFi down the road. No, I didn't actually see the dog in my yard." Just because it was the same dog (or dogs) the first two times does NOT mean it was the same one this time. Yes, I do realize it probably was, but you still need some sort of proof. You also don't know what kind of people you're going to make mad once you tell them that their dog did this thing. Will they have a gun? Will they punch you out? Will they follow you home and harm your kids? THINK before you act! And be safe!