Bloody Sunday

As in ”Sunday Bloody Sunday,” for those of us who get the bulk of our Irish history from Bono. On Jan. 30, 1972, British troops marched into Derry, Northern Ireland; by the time they left, several civilians were dead. Director Paul Greengrass goes to the root of ”The Troubles” for the story of Protestant march organizer Ivan Cooper and Catholic rebel Gerry Donahue.