In two parts:
Quote Originally Posted by Azor View Post
But how much evidence is there that Scappaticci was a British agent? The PIRA seems to believe his denials and he lives in Northern Ireland.
I would say there is evidence that Scappaticci was a British agent; possibly for ten years as the head of PIRA's "nutting" squad and he claims to have become inactive in republicanism in 1990. The key point for the current investigation was his activity protected and others died to do so. Evidence for that is likely to be more difficult. Will those involved in handling him (the Army) and the receivers of the information (MI5) have complete records which are handed over to the investigators?

Is there enough evidence to put him in court for murder for example?

Possibly noteworthy is that the Director of Public Prosecutions has recently been accused of being too ready to prosecute soldiers when paramilitaries are not. In the programme he explains why he has directed the investigation.

By Azor:
Perhaps the British were using him to cover for another source(s)? If so, was the British government subjecting him to risk of reprisal? Yet he is a murderer...
Quite possibly as many have commented PIRA was emasculated by the time of the Good Friday Agreement having been infiltrated at senior levels, although he had been active for many years by then.

PIRA was ruthless at times towards spies and suspected spies, but to acknowledge a central figure, the head of its own counter-intelligence "nutting" squad, was British spy would affect their credibility even today. Few really want to open this murky world.