Half Moon Investigations by Eoin Colfer
Fletcher Moon has never been like other kids, he has an unusual talent for sniffing out mysteries. It dosen't bother him in the least that even after graduating top of his internet class that he might possibly be the youngest certified detective in the world with a silver-plated badge to prove it.
When a classmate hires him to solve a crime, his badge is stolen and all sign point to the town's notorious family of crime the "Sharkeys". In order to solve the crime and get back his most prized possession, Fletcher must ally himself with the notorious Sharkeys and live undercover as one them. Fletcher has only twelve hours to slove the crime and clear his own name.
I hope that there will be more crimes that Fletcher will be there to solve.