LONDON – The disguised gunman who burst into an upmarket London jewellery store and carried out one of Britain’s biggest-ever robberies was sentenced to 23 years in jail yesterday, a year to the day after the heist.Amam Kassaye, 25, was part of a well-organised team that made off with £40 million (more than BDS$120 million) worth of gems from Graff Diamonds’ store on London’s Bond Street. The haul has yet to be recovered – and insurers have offered a million-pound reward for information leading to its recovery.Kassaye put a gun to the back of terrified shop assistant Petra Ehnar, forcing her to empty the store’s display cases and briefly taking her hostage as he and an accomplice ran out into the street.In court, Kassaye’s defence claimed that the August 6, 2009 robbery had not been carried out by him but rather “by someone remarkably like him”. But Ehnar identified him as the robber. Prosecutor Philip Bennetts told jurors that his facial features “would be etched in her mind forever”. (AP)