How to teach a 7 year old not to abuse animals?

My 7 year old neighbor had a little Chihuahua mix and abused her very much. He would put the leash on her and swirl in the air as if the leash was a lasso and he would throw her to the wall. He never gave her food or water and she was trapped in a little doorway that was about 2 feet wide and 3 feet long. It broke my heart when he would hit her with his hammer and choke her. It brought me to tears. Many people saw him torturing her and he got reported to the animal police people. I often tried to talk to him and say that thats very cruel and he should be more gentle with her. His mother never said anything when he did was torturing her. When the animal shelter people came, the boy was in school so they told the mother that he had been reported (i was at home baking cupcakes and heard them outside). But they didnt really do anything. they just told her to tell her son to be more careful. His pup often escaped from the little doorway to come play with me and my puppy. Of course after a while of playing I would knock on their door and take her back to them.

Two days later (after the boy got reported) the boy told me that his puppy died to bleeding. I’m guessing he killed her with his hammer. And now he has ANOTHER dog. Hes much bigger than his old pup, and much stronger so he doesnt really get hurt when the boy is trying to hit him with the leash. This dog also escapes from his doorway and runs to me everyday when I’m about to go to school. I never really played with the dog but for some reason dogs trust me. I’m doing a story on animal cruelty for school but I wanna know how I can get the boy to stop torturing animals.
Oh and I’m only 13 years old.
im sure the boy isnt being abused. he’s just spoiled. he gets whatever he want. HES SEVEN YEARS OLD AND HE HAS A LAPTOP!! and he doesnt have a dad (well he does but the mother is cheating on him with a bunch of other guys. hes almost never at home)