Serious mistakes and failings by officers and soldiers led to the deaths of 13 civilians on Bloody Sunday, the head of the British Army has said.
General Sir David Richards said the Saville Inquiry left him certain that the victims did nothing that could have justified their shooting.
In the 38 years since that tragic day's events, lessons have been learned, he said, adding: "The way the Army is trained, the way it works and the way it operates have all changed significantly".
Casualties of the Bloody Sunday killings were down to some soldiers “losing their self control,” British prime minister David Cameron said.
Speaking at the publication of the report into the killings, Mr Cameron said the Saville Inquiry had found the actions of British soldiers was “both unjustified and unjustifiable".
The inquiry found the order that sent British soldiers into the Bogside, the scene of the killings, “should not have been given”.
This order should not have been given as it was contrary to the orders received from Brigadier MacLellan, the report found.
"Colonel Wilford either deliberately disobeyed Brigadier MacLellan’s order or failed for no good reason to appreciate the clear limits on what he had been authorised to do".
The report also found that the “soldiers were not justified in shooting any of the casualties”.
It said that five of the soldiers had fired their guns in the belief that no-one in the area towards which they were firing posed a threat, or not caring whether or not anyone there posed a threat.
It found that two of the soldiers fired "in the belief that they might have identified gunmen, but without being certain that this was the case".
The Inquiry found that Lance Corporal F had shot Michael Kelly, but said the question remains whether he believed that he was justified in firing.
"We have considered whether Lance Corporal F fired in panic or fear, without giving any proper thought to whether he had identified a person posing a threat of death or serious injury, but in our view this was not the case, since he was with other soldiers and a considerable distance from his target; and had no reason to believe that he or his colleagues were in immediate danger".
Corporal P was found responsible for the shooting of one or more of the casualties William Nash, John Young and Michael McDaid.
The report said it was also possible that Lance Corporal J and Corporal E could have hit William Nash, John Young or Michael McDaid.
Private U was found to have shot Hugh Gilmour knowing that Hugh Gilmour was not posing a threat of causing death or serious injury, or not caring whether or not he was posing such a threat.
One of Privates L or M was said to have been responsible for the death of Kevin McElhinney.