The perpetrators of hundreds of unsolved murders in Northern Ireland are unlikely to be brought to justice, the police chief has said.
Hugh Orde: Many murders will remain unsolved
Chief Constable Hugh Orde suggested that a type of truth and reconciliation process may be needed to bring closure to the past.
More than 1,800 killings, half of those carried out during 30 years of the Troubles in the province, remain unsolved.
But Mr Orde said there were difficult choices to be made between policing the present or investigating the past.
He said he would not have the resources to review 1,800 killings.
In an interview for the BBC, Mr Orde said: "The numbers of officers I would have to employ to carry out that job is simply unachievable.
"My primary focus is to prevent any more murders taking place, reduce the opportunities for serious crime, and to investigate the most recent murders."
The older the case is, the harder it is to solve in an evidential format
On the issue of a truth and reconciliation forum, Mr Orde said: "There needs to be something that gives everyone an opportunity to say their piece, to get the best explanation they can on what happened to their families, their loved ones, so that they can then get on with their lives."
However, he said it would not be satisfactory for everyone.
"I've met families that want a wide spectrum of outcomes - be it...revenge...at the other end - simple understanding, with no blame attached," he said.
"It's a debate which is partly academic, it's partly practical but it does need to happen."
A truth and reconciliation forum was set up in south Africa after the end of apartheid. It granted amnesty to many of those whose testimonies it heard.
Mr Orde said a large number of past cases were already being reviewed.
But, he said, difficult decisions would have to be made.
"We will look at cases where the chances of success - due to forensic advancements or witnesses coming forward - give us a chance of a positive outcome," he said.
"The longer a case goes on, the older the case is, the harder it is to solve in an evidential format."