The Historical Enquiries Team has published a review saying that an IRA volunteer shot dead by British troops on the streets of Belfast 40 years ago was unlawfully killed without justification.
Joe McCann, 24, a member of the Official IRA, was unarmed and running away when he was shot by members of the Parachute Regiment in the Markets district on April 15 1972.
Mr McCann was one of the Official IRA's most prominent members and his unit's seizure of the Inglis bakery in Belfast holding off hundreds of British troops during internment raids became part of Republican folklore.
Two Royal Ulster Constabulary Special Branch officers recognised a disguised Mr McCann near the city centre and attempted to arrest him on suspicion of attempted murder, asking nearby soldiers for assistance.
Mr McCann ran off. Evidence from police and soldiers was that they shouted at him to stop or they would open fire. After he failed to halt, three paratroopers opened fire and he was hit a number of times.
But the Historical Enquiries Team said on Tuesday that it considered "Joe's actions did not amount to the level of specific threat which could have justified the soldiers opening fire in accordance with the army rules of Engagement or their standard operating procedures."
The team also accused the RUC of failing to properly investigate the killing of the married father-of-four.
It said: "The original investigation into Joe's death was rendered ineffective as a result of the flawed investigative policy that has been agreed between the military and the chief constable in the early 1970s, whereby the Royal Military Police interviewed soldiers in isolation from the RUC investigative process."