They were there on legitimate business. The man was taking care of the dog and they were there to pick it up. He shot past his property line killing a woman in her car. Sounds like out and out murder. Lock him up and throw away the key.
It didn't sound like it to me. It sounded like the old man promised the late husband he would never let his estranged wife get the dog. When the wife sent her brother there to take the dog, the old man snapped.