The fact that you never reported this dog in over 4 months is a problem. The fact that you put your dog inside the house, picked up your gun, and went outside again to shoot the dog is a huge problem. That means you didn’t need to shoot the dog at all for your protection or your dog’s protection. You came back out to shoot it when it was not necessary. You have a lawyer, which is good. Given the facts as you’ve described them, you definitely need a good lawyer.