On 30th January 1972, 13 people died when British soldiers opened fire on civil rights marchers in Derry, Northern Ireland.
The day became known as Bloody Sunday.
The Widgery Inquiry in 1972 inquiry was regarded as a whitewash by nationalists.
In 1998 a fresh investigation was announced. The Saville Inquiry into Bloody Sunday became the longest-running and costliest inquiry in British legal history.
15 June 2010 PM David Cameron tells MPs the Saville report shows the shooting dead of 13 marchers on Bloody Sunday was "unjustified and unjustifiable".