Based on the information provided within the question it can be said that in order for a certiorari or appeal, a minimum of four of the nine justices need to vote for it. This is usually referred to as the "rule of four". Studies have shown that the courts deny most of the petitions that usually only takes about 100 cases each term.
I think you should ask your sister a little more of what happened and why he did it. Then you should go find the boy and perhaps talk to his parents cause it's not right for him to do that.
