I feel really really sorry for Burke. He was just a young boy and he's had the finger pointed at him over and over again. If he did hit her with the torch I'm sure he didn't mean to kill her, he was probably just a kid acting out. If the parents hadn't tried to cover it we wouldn't even know their names.
But there's also an excellent chance he didn't do it. And his whole life was pretty much destroyed by the actions of someone else. He lost his sister. He probably lost his friends. He lost his privacy. It's very sad.