Blunder reveals identity of anonymous witness

A prisoner has refused to give evidence against three murder suspects accused of stabbing an inmate to death at HMP Pentonville after his true identity was revealed, a court heard. The witness had begun to tell jurors what he saw before Jamal Mahmoud, 21, was allegedly slaughtered with ‘calculated brutality’ at the prison in Islington, north London. He claimed Congolese gangster Basana Kimbembi, 35, held up a 15 inch knife and threatened the victim before he was fatally stabbed in…