It's one of the most audacious diamond heists in British history: despite CCTV, alarms and security guards, a six-man gang spent the Easter weekend breaking into a vault in London's Hatton Garden, escaping with the contents of safe-deposit boxes estimated to be worth millions. But how did they get away with it? Declan Lawn takes a journey into Britain's criminal underworld in search of the secrets behind the job -... see more