Re: They waited till he turned baaligh...
I really don't think they killed the kid because they really thought it was a just punishment. There's gotta be more to the story..
Since the victim was from an "influental" family, my guess is that they just arrested the first suspect they could think of and already made the decision to use him as a scapegoat regardless of what the truth was.
It really makes me sick to read these kind of stories, that mostly come from Saudi Arabia. May Allah guide the Saudis to the right Islamic path, because currently they are far away from it.