One of the most intriguing questions to be raised over the blood-splattered events between internment in August 1971 and the final day of January 1972 was if any of the soldiers who fired fatal shots in Ballymurphy were the same ones who unleashed live rounds into the bodies of unarmed civilians on Bloody Sunday.
We know for a fact that the Parachute Regiment was involved in both mass shootings in west Belfast and later in Derry. Campaigners for the victims of the former atrocity have constantly highlighted the possibility that troops who shot their loved-ones may have been in the same unit as those that caused such carnage on the Bogside six months later.
One of the reasons they are demanding a public inquiry into the 1971 massacre is that an investigation might throw some light on whether or not the same paratroopers were, indeed, involved.
It is a bitter irony that the preliminary inquests into the Ballymurphy events started this week – just days after the fallout from the revelations about the 'letters of assurance' to IRA on-the-runs (OTRs), which effectively gave the likes of John Downey de facto amnesty.
Much of the outrage over this secret scheme focused on that of unionists, but they were not alone in speaking out against the OTR deal.
Three Irish government ministers (speaking anonymously) in the Fianna Fail-Progressive Democrat administration at the time the deal was sealed have insisted that, while they knew the British and Sinn Fein were wrestling with the problem of the 187 IRA fugitives, they weren't aware of the existence of the letters.
Others, too, confirmed this – including the SDLP, which has pointed out the ramifications of this deal. Mark Durkan and Alex Attwood claim that the letters have now created a climate in which it may be near-impossible to prosecute others for past Troubles crimes.
This, after all, is why they objected in the first place to a deal based on legislation for the 187 as, in their view, it would indirectly ensure others (such as soldiers and police officers) involved in state violence would be entitled to parallel de facto amnesties.
Peter Hain (below) has already come under fire since the deal was exposed in the Old Bailey last week for not only defending it, but also claiming other parties (and, presumably, that means the-then Irish government) were also aware of the scheme.
Inevitably, Tory backbenchers demanded that the soldiers accused of shooting civilians on Bloody Sunday be granted amnesties, too.
Hain then intervened in the wider question of how to deal with those accused of past Troubles offences.
He went to The Sunday Telegraph – a newspaper read by the military officer class, retired and still serving – not only to defend the deal, but also suggest that, in order for all to move on, even the Bloody Sunday soldiers be granted amnesties.
In one sense, Hain is correct – if one holds a logical position in that you cannot say amnesties for one side, or at least those on Sinn Fein's wish-list, and continued prosecutions for all others involved in the conflict.
But logic and reason, of course, are so often trumped by emotion and pain in the post-peace process Northern Ireland.
Moreover, it is easy in the abstract to point out the illogicality of amnesties for some and ongoing due process against others – especially if you didn't lose a loved-one, or close friend, during the Troubles. The victims of Bloody Sunday this week reminded us that they have already been through due process – the Saville inquiry – which came to hard conclusions in a judicial context.
The remaining survivors have also stressed that they will seek their day in criminal court against the soldiers – even if the current police inquiry is expected to last at least another four years.
Yet the impact of the OTR letters has, paradoxically, provided one set of British soldiers with logical and, possibly, legal shields to ward off being prosecuted in court, while the families of other soldiers, specifically those killed at Hyde Park in 1982, are denied justice.
Because the lawyers for the ageing ex-paratroops both on the Bogside and, possibly even before that, in Ballymurphy, will argue for consistency and logic when it comes to any attempt to try them in court.
The soldiers now have a compelling and very watertight case to argue – even if this results in no justice for the families of those cut down by the forces of a state that was meant to be protecting them.
It is true that, throughout the Troubles, there has already been a de facto amnesty in existence for members of the security forces.
You think of the disgracefully lenient treatment of Private Ian Thain who murdered Thomas 'Kidso' Reilly in cold blood in west Belfast more than 30 years ago, or the lack of prosecutions in the 'shoot-to-kill' scandals.
Now that unofficial policy of not pursuing the forces of the state who committed criminal acts in uniform and out of it has been bolstered by a deal designed to quietly let their old adversaries in the Provisional IRA get on with their lives.
As the man said, you couldn't make it up.