A coroner ruled on Tuesday that 10 people killed in disputed shootings involving the British army in Belfast 50 years ago were “entirely innocent”, drawing a line under one of Northern Ireland’s longest-running inquests.

The people were killed in the Ballymurphy massacre in a series of five separate incidents between August 9 and 11 in 1971 during the early years of the Troubles, three decades of violent sectarian conflict in the region that ended with the 1998 Good Friday Agreement.

The coroner, Justice Keegan, found the army responsible for nine of the 10 deaths. In the case of the 10th victim, a former soldier John McKerr, Keegan said there was insufficient evidence to determine where the shot that killed him came from.

An 11th died of a heart attack following an altercation with soldiers. The deceased included men and women aged between 19 and 49. One was a priest.

Efforts to investigate the deaths at the time were dismissed as “entirely inadequate” by Keegan. No one was prosecuted for the violence.

“The principal findings have cast a tremendous new light on one of the darkest pages of the history of the conflict, and will come as an immense relief and vindication for the families,” Ireland’s foreign affairs minister Simon Coveney said on Tuesday, praising the “determined campaign” of the victims’ families to uncover the truth.

Sinn Féin’s Michelle O’Neill, Northern Ireland’s deputy first minister, tweeted that “the victims and the families of the Ballymurphy massacre have been vindicated and the truth laid bare. This was British state murder.”

In the first incident, on August 9, Father Hugh Mullan, a 38-year-old remembered by his family as a gifted Latin teacher, and Francis Joseph Quinn, a 19-year-old father of one, were shot by British servicemen amid rioting in the Springfield Road.

Keegan said Mullan was “unarmed, not acting in any way as a threat, attending to a wounded man in the field and waving a white object as a sign of his peaceful intentions”. Quinn was also described as “unarmed, and not acting in any way as a threat”.

The second incident, also on August 9, resulted in the deaths of Joan Connolly, 44, Daniel Teggart, 44, Noel Phillips, 19, and Joseph Murphy, 41 near an army barracks. All four died from gunshots and all four were described as neither armed nor acting in a threatening way.

In the third incident, 31-year-old Edward Doherty was shot dead while in the proximity of petrol bombers by a soldier who did not give reasonable warning or follow the army’s protocols, the coroner said.

In the fourth incident, during the early hours of August 11, 43-year-old Joseph Corr and 20-year-old John Laverty, who were not acting in a threatening manner, were shot dead by soldiers.

The final verdict covered the death of McKerr, 49, on August 11. “Mr McKerr was not doing anything which could have caused someone to think him a threat or which justified the use of lethal force against him. He was clearly unarmed,” the coroner said.

Tom Cloonan, a security analyst and former captain in the Irish army said the tactics used by the British army at the time were known to be “threat multipliers” by assuming “very provocative” postures at times of conflict. “What happened in Ballymurphy doesn’t come as a surprise. It was a turkey shoot,” he added, describing how the mixed profile of the victims showed the indiscriminate nature of the force used.

The conclusion of the inquests came as the British government used the Queen’s Speech to set out plans to introduce “legislation to address the legacy of the Troubles in Northern Ireland”.

“It is clear that the current system for dealing with the legacy of the past is not working well for anybody, with criminal investigations increasingly unlikely to deliver successful criminal justice outcomes, and failing to obtain answers for a majority of victims and families,” the government said.

But the government stopped short of confirming plans for an amnesty, which provoked outrage in Northern Ireland and the Republic when they were leaked last week, and promised to “work with all relevant stakeholders, including the parties in Northern Ireland and Westminster, the Irish government and civil society, including victims groups, as part of this process”.