A new police inquiry into the Bloody Sunday killings in Northern Ireland 40 years ago will involve a team of 30 detectives. But there are concerns that it will be under-resourced.
Please wait while this video loads. If it doesn't load after a few seconds you may need to have Adobe Flash installed.
The probe into one of the most controversial days in Northern Ireland's history, when British soldiers opened fire on civil rights demonstrators in Londonderry, has not yet begun and will take four years to complete.
Thirteen people died on the day in January 1972.
The murder investigation follows the highly damning Saville inquiry report, which strongly criticised the actions of the army.
The report, published in 2010, found that no warning was given to civilians before soldiers opened fire, that some of those killed or injured were clearly fleeing or going to the aid of others, and that none of those killed posed a threat or was doing anything that justified being shot.
The Police Service of Northern Ireland has consulted prosecution lawyers as it prepares to open an investigation, which would require a team of 30 and extra specialist resources.
Waiting for justice
Assistant Chief Constable Drew Harris said the matter would need to be brought to the Policing Board which oversees policing in Northern Ireland to assess priorities.
Mr Harris said: "There is not the expertise free and available to undertake an investigation of this size and that is why we are faced with dilemmas around prioritisation.
"The special resources required for this scale of investigation are just not available at this moment to commence an investigation of this scale and length of time. It is an undertaking which will take perhaps three to four years."
Sinn Fein North Belfast Assembly member Gerry Kelly said the investigation was a huge issue for the Bloody Sunday families and he was worried about potential delays.
"People have waited a long time for justice in terms of this. The question I want answered is when will we move this ahead, saying they are not ready to move this ahead will be very worrying for everybody," he said.