Graphic CCTV: The moment a 15-year-old boy was stabbed to death as teen tried to steal his bicycle

A teenager has been found guilty of stabbing a 15-year-old boy to death as he tried to steal his bicycle. Joshua Williams, 18, lashed out with a blade as popular young student Alan Cartwright (seen wearing a blue top) "innocently" rode along Caledonian Road, north London, with his friends in February. At the time of the attack caught on graphic CCTV, Williams had been on police bail on suspicion of possessing a four-inch lock knife although he was never charged.