David McKittrick: A crucial witness has broken ranks

Soldier 027 is a crucial witness at the Bloody Sunday tribunal because he is the only military witness at or near the shootings who departs from the line that all shots were fired at identified gunmen or bombers.

While he says the shootings were unjustified, all of his former Parachute Regiment colleagues are about to testify that their actions were justified.

Although the possibility exists that other soldiers may yet come forward to break ranks, he stands alone among those who were actually in the Bogside in saying troops had no reason to open fire.

He is therefore expected to face intense pressure when he is cross-examined, probably next week, by counsel for other soldiers. If his evidence is judged to stand up to such scrutiny, it will obviously throw great doubt on other military testimony.

Before this happens he will continue to be led through the remainder of his written testimony by Christopher Clarke QC, counsel to the inquiry.

Counsel for other soldiers may be expected to dwell on the discrepancies between statements he made shortly after Bloody Sunday, when he said he saw a gunman and a bomber, and his present evidence, in which he says he saw neither.

Scores of other soldiers are to testify that fire was opened only after troops came under heavy fire from IRA snipers and bombers in Londonderry in January 1972. The soldiers who actually opened fire will say they fired only aimed shots at identified targets during what was in effect a heavy firefight with the IRA.

This picture of events has been generally contested by civilian witnesses. Sinn Fein's Martin McGuinness, who has admitted to the tribunal that he was second-in-command of the IRA in the city on Bloody Sunday, is to testify that the organisation's members did not open fire.

Soldier 027 was one of the witnesses who came forward several years ago during investigations by Channel 4 News. He appeared on television in silhouette and with his voice disguised.

The question of high-level involvement in the run-up to Bloody Sunday will be examined in the months ahead when the inquiry takes evidence from former ministers and other political figures.

But the construction that may be placed on Soldier 027's evidence is that it places responsibility not on senior figures in the army or the government, but on just two soldiers. One of these is believed to be dead.