On November 21, 1974, the Provisional Irish Republican Army detonated bombs in two pubs in Birmingham, England, as part of its campaign to get the British out of Ireland. Twenty-one people were killed, and nearly 200 were injured. It was at the time the deadliest attack in England since the days of V-2 rockets. The police immediately sprang into action, arrested six completely innocent Irishmen, and coerced confessions from them. When the men challenged their convictions, the leading judge of his generation, Lord Denning, threw out their appeal, despite substantial evidence of police misconduct and actual innocence.

If the six men win, it will mean that the police were guilty of perjury, that they were guilty of violence and threats, that the confessions were involuntary and were improperly admitted in evidence and that the convictions were erroneous.... This is such an appalling vista that every sensible person in the land would say: It cannot be right that these actions should go any further.

An appeal might expose holes in the British justice system, and therefore it was not allowed to happen. Not until 1991 were the men finally freed.

London Falling: A Mysterious Death in a Gilded City and a Family’s Search for Truth