The first hearings of the Bloody Sunday Inquiry of this year will take place today in Derry.
The inquiry, chaired by Lord Saville, is investigating the shooting dead of 13 civilians by paratroopers in 1972. A fourteenth civilian died from injuries received during the shooting.
Civilian witnesses are still giving evidence to the inquiry about the entry of paratroopers into the Bogside.
The tribunal must also resolve whether or not attempts to curb publication of sensitive intelligence material will enable it to get to the bottom of what happened on Bloody Sunday.
Shortly before Christmas, concern was expressed about whether or not documents relating to security service agents and offices should be revealed.
Two British ministers have submitted public interest immunity certificates, which would restrict publication of material about two security service agents and their handlers.