The Accused by John Grisham (Theodore Boone #3)

Theodore Boone is the thirteen year old who knows more about the law than most adult lawyers. He certainly never expected to be the victim of crime himself. But then his bike is vandalised, he's attacked while doing his homework and, worst of all, framed for a robbery.
When stolen computer equipment turns up in Theo's school locker, the police start leaning on him hard. And he is the only suspect. What if he is found guilty? What about his dreams of becoming a lawyer? In a race against time, aided by his renegade uncle, Ike, Theo must find the real felon and reveal the true motivation behind the crimes of which he stands accused.