The events on Bloody Sunday strengthened the Provisional IRA and increased nationalist resentment and hostility towards the British army, the Saville Inquiry has found.
The report into the killings, which was published today, said there was no evidence that any member of the Provisional IRA used the march to engage security forces with guns or bombs.
“Nevertheless, we consider it likely that Martin McGuinness was armed with a Thompson sub-machine gun on Bloody Sunday and we cannot eliminate the possibility that he fired this weapon after the soldiers had come into the Bogside”.
However, the report went on to say it was unlikely that Northern Ireland's deputy first minister engaged in any activity that provided soldiers with a justification for opening fire.
Speaking today, Mr McGuinness denied having a machine gun on the day.
He said the report had cleared everybody in the city: “He [Lord Saville] fully pointed the finger of blame for what happened directly at the British Parachute Regiment".
The inquiry said it had no doubt there was significant Official IRA activity in the areas where shootings took place, but found this “did not provide an explanation for why soldiers targeted and hit people who were not posing a threat of causing death or serious injury”.
It found that, with the exception of the shot fired by the Official IRA at a soldier near a Presbyterian Church, there was no evidence that other members of the Official IRA engaged security forces with guns or bombs.
TUV leader Jim Allister said the finding that Martin McGuinness was probably armed with a machine gun did not surprise him, adding "it confirms my view of his perpetual unfitness for government".
Sinn Féin president Gerry Adams said: “The facts of what happened on Bloody Sunday are clear – the British Paras came to Derry and murdered 14 civil rights marchers and injured 13 others. They [the marchers] were unarmed, they posed no threat and they were completely innocent”.