Sounds like a good case of Shoot, Shovel, and Shutup to me

In reality, it would be very very very wise of the guy if he took the dog to the vet and had it take a long nap without anyone saying anything to him....If he isn't that smart, I personally wouldn't let law into it, I would take it into my own hands and there would be posters hanging around for a "missing dog"

I've had this happen to me before, only it was my dog that did it. When I was around 10 or so the neighbor girl, and a few others were at my place playing basketball. My lab loved to try to steal the ball, etc. And he jumped up and his dew claw left a scratch on the neighbor girls back. She went crying home and told her parents that my dog "bit and attacked her" next thing you know he pulls in the yard, puts the 22 out his car window and shoots my dog at point blank range right in front of me. Her cat disappeared a few days later.......Never did find out what happened to it