Three teenagers have received custodial sentences for the manslaughter of a man they lured to a Kent beach and killed, believing him to be a paedophile. At the Old Bailey on Thursday, a 16-year-old girl and a 16-year-old boy each received seven years in custody, and a 15-year-old boy five years, for the manslaughter of 49-year-old Alexander Cashford in Leysdown-on-Sea, Isle of Sheppey, on August 10 last year. Prosecutors outlined how Mr Cashford was chased and attacked with rocks and a bottle, found lying face down in mud. The court heard he met the 16-year-old girl at around 7pm on the seafront, and was dead just over an hour later. Mrs Justice Cheema-Grubb said the incident began as "a bit of mischief" by teenagers on holiday, but escalated into "dangerous misconduct which risked and ultimately took a man’s life." The sentences were delivered to a packed public gallery, with cries heard from the dock.…