A Wild West-style shoot-out occurred in the centre of Glasgow on Tuesday, May 4th, 1921, when a police convoy, taking an IRA prisoner on the first stage of his journey back to Ireland for trial, was ambushed by three separate IRA gangs.

Some of the police who were armed returned the bandits’ fire. With guns blazing on all sides in Cathedral Square it was a miracle that only one man died. He was Police Inspector Robert Johnston.

Three months later 13 men stood trial for the officer’s murder. But by that time the government had signed a truce with the IRA and after an 11-day trial six were found not guilty and the charges against the other seven were all “not proven.” That left the case, officially at least, unsolved.