People mark the anniversary of Bloody Sunday in Londonderry in 2011.Cathal McNaughton / Reuters

More than 40 years after unarmed civil-rights marchers were shot to death by British soldiers in Northern Ireland, police have made an arrest in the incident.

Investigators detained a 66-year-old man in County Antrim on Tuesday in connection with the 1972 Bloody Sunday massacre of 14 people, the Police Service of Northern Ireland said. The man, whose name was not released, was questioned at a police station in Belfast. A police statement quoted Detective Chief Inspector Ian Harrison, the officer leading the investigation, as saying the arrest “marked a new phase in the overall investigation which would continue for some time.”

The BBC reported the man is a former member of the Parachute Regiment, and was referred to as “soldier J” in a British government inquiry into the shooting. No soldiers present at the shooting have been arrested and tried for the events of Bloody Sunday.

On January 30, 1972, thousands of Northern Ireland Catholics marched in the city of Londonderry to protest the British policy of arresting and imprisoning without trial suspected Irish nationalists. British army paratroopers fired into the crowd, killing 13 people and wounding 17 others. A 14th victim died of his injuries some months later.

The massacre occurred during the Troubles, the decades-long sectarian fight over the status of Northern Ireland; Protestant loyalists wanted Northern Ireland to remain within the United Kingdom, while Catholic nationalists sought to form a united Ireland. The conflict mostly ended in 1998 with the Good Friday agreement, a peace accord reached by the British and Irish governments and several political groups from Northern Ireland that halted the violence and defined Northern Ireland’s current system of government. More than 3,600 people died in the conflict.

An inquiry launched shortly after Bloody Sunday—and later considered a “whitewash”—cleared the British army of wrongdoing and said the protesters were armed. A second inquiry, established in 1998 by former Prime Minister Tony Blair and led by jurist Lord Saville, exonerated the victims. The findings, published in 2010, determined the demonstrators posed no threat to the British army and that soldiers “lost control” and fired without warning. The report also found that some of those killed or injured were attempting to flee or help the injured. When the results were released, Prime Minister David Cameron apologized for the “unjustified and unjustifiable” killings. In 2011, the British government announced it would pay compensation to the relatives of the victims.

A New York Times account from the day after the massacre described the scene at Londonderry. One person present said:

The speakers threw themselves to the platform and I shouted for people to keep down. I could see the army systematically picking off people who had got up to run away. There was complete panic and confusion, and I thought the best thing I could do was to tend to the injured with a friend. I was carrying a white pillowcase. We were both fired on and my friend was hit on the side of the face.

Tuesday’s arrest was made by a branch of the Police Service of Northern Ireland that was given the task in January of investigating unsolved murder cases dating from the beginning of the Troubles until 2004, according to the BBC.

John Kelly, whose 17-year-old brother Michael was killed on Bloody Sunday, told the Times Tuesday that “all of the families of the victims are very excited” by the arrest and that “we expect all of the rest of those responsible to be brought in and prosecuted.” Kate Nash, whose 19-year-old brother William was killed, told the BBC that “there is a flicker of hope. It’s a very positive step.”

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