Thirteen people were killed when soldiers from the Parachute Regiment opened fire on marchers during a civil rights march in Derry on 30th January, 1972.
The Saville Inquiry into the events of what became known as Bloody Sunday was announced in 1998, and will deliver its findings in 2010.
BBC News profiles the prominent legal figures involved in the Saville Inquiry.
LORD SAVILLE OF NEWDIGATE
Lord Mark Saville is a member of the Supreme Court and the chairperson of the Bloody Sunday Inquiry.
Born in 1936, he was educated at Rye Grammar School and Brasenose College, Oxford.
He obtained first class degrees in law, and was called to the Bar in 1962.
A 1991 survey found he was one of the High Court judges whose judgements was least likely to be overturned.
He was appointed as a Law Lord to the House of Lords in 1997, and when the inquiry into Bloody Sunday was announced the following year, he became its chair.
Renowned as both as a gifted lawyer and a moderniser, he ensured the latest technology - including a computer-generated 3D model of the Bogside - was made available to the inquiry.
In 2009 he was selected as one of 12 judges to sit on the newly-created Supreme Court.
Lord Saville has spent six years compiling his report into Bloody Sunday.
Professor Michael Mansfield QC is a civil rights lawyer who has represented a string of high-profile defendants and many of the Bloody Sunday families.
Born in 1941, he emigrated to Australia and worked as a dustman before realising his life lay in the law.
He was called to the Bar in 1967 aged only 26, and rapidly established himself as one of the most promising young lawyers of his generation.
He quickly built up a reputation as "the defender of the indefensible", and in 1972 had his first high-profile client - an alleged leaders of English anarchist group the Angry Brigade - acquitted.
He went on to defend the Birmingham Six, many of the miners caught up in the 1984-5 strike, the family of Stephen Lawrence and Barry George, who was accused of the murder of Jill Dando.
He is also a best-selling author, and wrote his autobiography, 'Memoirs of a Radical Lawyer', in 2009.
SIR LOUIS BLOM-COOPER
Sir Louis Blom Cooper is a leading QC who represented the Northern Ireland Civil Rights Association at the Saville Inquiry.
Born in 1926, he was educated at King's College London, the University of Amsterdam and Fitzwilliam College, Cambridge.
A former columnist with The Observer, he was involved in the foundation of Amnesty International in 1961 and was an academic at the University of London from 1962-84.
In 1992 he was appointed by the Secretary of State for Northern Ireland as the first Independent Commissioner for the Holding Centres.
He has also been a Judge in the Court of Appeal of Jersey and Guernsey, and has chaired the Mental Health Act Commission.
Edwin Glasgow QC represented many of the soldiers who gave evidence to the Saville Inquiry.
Born in 1945, he was educated at University College, London, and became a fellow in 2004.
He is a member of the International Court of Appeal as well as Harlequins FC and the London Opera Players.
Hon. Mr Justice Christopher Clarke QC was the lead counsel to the Bloody Sunday Inquiry.
Born in 1947, he was educated at Marlborough College and Conville and Caius College, Cambridge.
He was called to the Bar in 1969, and became a QC in 1984.
Since 2005 he has been a High Court Judge.
His opening statement to the Saville Inquiry in 2000 was the longest in British legal history.
Closing the Inquiry, Christopher Clarke said he hoped it had played a part in enabling people to come to terms with the events of the day, and hoped it had held to account people "whose actions or inactions contributed to what happened".