Bit of a spoiler here:
The tone that was set from the beginning makes it feel like we'll be told something at one point to help us understand. But instead, all we're given is vague background information for the kid and his family, and some people around him, and a cheeky attorney who seems more in it for teasing everyone. He goes back and forth with the interviewer about how he knows that if we knew what he knows, we'd feel sympathy for the kid, but then refuses to give any more information.
This series started off very interesting, and ended extremely flat and unfulfilling, if the whole idea of this thing was "We'll never know" they didn't need a four part series for that, an article would have been fine.