MI5 could not have prevented Fishmongers’ Hall attack, inquest told

Senior Security Service figure says there was nothing it could have done to change the outcome in this case

A senior figure at MI5 has said the Security Service could not have prevented Usman Khan's deadly attack at Fishmongers' Hall in London, despite knowing that he wrote a play telling of a series of knife murders.

Khan killed Jack Merritt and Saskia Jones at a prison education event at the hall in November 2019, within a year of being released on licence for terrorist offences. An anonymous MI5 officer referred to as Witness A told an inquest into their deaths that an intelligence service review of the attack concluded MI5's actions were sound".