Soldier F is accused of murdering James Wray, 22, and William McKinney, 26, as well as five counts of attempted murder in 1972. Soldier F is further accused of attempting to murder Patrick O'Donnell, Joseph Friel, Joe Mahon, Michael Quinn and an unknown person. Soldier F, he said, was "part of a small group of soldiers who moved west from Rossville Street into that courtyard". The key evidence in the Soldier F case is statements given by other soldiers at the time of Bloody Sunday. Who is Soldier F?