Detectives have today arrested a 69-year-old man on suspicion of murdering a pensioner – 11 years after her death. Una Crown was stabbed numerous times and her body was set on fire in the hallway of her bungalow in Magazine Lane in Wisbech. The 86-year-old’s body was discovered on Sunday, January 13 2013. Police have said that a man was arrested this morning on suspicion of Una’s murder and he remains at Thorpe Wood Police Station in Peterborough. Last year – 10 years since Mrs Crown’s murder \- police offered a £20,000 Crimestoppers reward for information which appeared on national television…