Yesterday the case against two former paratroopers over the killing of John McCann, an Official IRA commander, in 1972 collapsed due to a lack of fresh evidence.

At Langanside Courts in Belfast, Mr Justice O’Hara ruled the evidence “inadmissible” almost 50 years after Soldier A and Soldier C first gave statements, and said material from 1972 had been put before the court “dressed up and freshened up“.

The case has inevitably been incredibly divisive. McCann’s family have accused the state of “failure” at “all levels” over the lack of prosecution.

In the meantime, there’s growing anger in Westminster about veterans being taken to court. Johnny Mercer, the former veterans minister who recently resigned over the Government’s handling of the investigations into the Troubles, called the trial “farcical”.

Soldier A and C’s was the first prosecution around the Troubles shooting since the Good Friday agreement of 1998, but currently over 200 veterans, many of whom are in their seventies and eighties, are at risk of criminal investigations too. Soldier A and C’s legal team had warned in 2016 that earlier evidence from their clients would not be admissible (the soldiers gave statements in 1972 and subsequent ones in 2010), so it raises the question of how the case reached the court – and what else could follow.

Barra McGrory, formerly the Northern Ireland director of public prosecutions, was behind the decision to press ahead with the prosecution, who it’s been pointed out represented Gerry Adams and Martin McGuinness while in private practice. Mercer has been critical of the PPS, and asked for “an urgent independent inquiry to establish whether [its] decision was made ‘properly and correctly’.”

Clearly the Government needs to take decisive action, with legislation expected in next week’s Queen’s speech. But it must strike a careful balance, which respects Northern Ireland’s judicial structure (such as having its own Attorney General) relating to its delicate political settlement, while stopping veterans’ cases dragging out for years.

One solution that could create much-needed balance was proposed in 2019 by Lord Caine, formerly an adviser to six secretaries of state for Northern Ireland. His idea was to apply a modified version of Section 3 of the Criminal Law Act (Northern Ireland) 1967 and the common law on self-defence, an idea which John Larkin, Northern Ireland’s Attorney General, raised that year in a lecture.

The modification would help legal authorities distinguish between “a split second error of law on the one hand, and the execution of an act of studied illegality on the other.”

Caine proposed that once a legal authority could make distinctions on these complex cases, this could in turn be used for a certificate system. He wrote: “A certificate could only be issued if that legal figure were to conclude that a person potentially under investigation or facing trial had not honestly believed that the action he or she took with lethal or injurious effect was reasonable in the circumstances. If no certificate were to be issued, the investigation or proceedings would cease. Should a certificate be issued, the investigation or proceedings continue in the normal way.”

Elsewhere, there have been proposals for the Government to create a new investigative body to look through the files of 3,600 Troubles deaths and remove cases where there is no compelling evidence. But it could take a long time – during which veterans’ desperately need an end to the ongoing situation.

While reportedly some ministers think the Caine certificate system goes too far, Downing Street seems to be struggling around any proposal at all. Yet its paralysis could prove as politically risky as trying to override the judicial processes that brought Soldier A and C to court.