Michael McKinney, Jean Hegarty and John Kelly, like all the close relatives of the Bloody Sunday victims, have waited more than 40 years for justice.

On Thursday morning they, along with other families, will gather beside the rain-stained memorial to the 1972 shootings in the Bogside. Together they will walk to Derry’s neo-gothic Guildhall after learning whether Northern Ireland’s Public Prosecution Service will bring murder charges against the paratroopers who shot dead their brothers.

The expectation is that three or four former soldiers from the Parachute Regiment’s 1st battalion will face prosecution for opening fire on the civil rights demonstration. Thirteen men were killed that afternoon, and a 14th died from his injuries later.

McKinney, 67, a taxi driver, recalls his older brother, Willy, then 27, joining the protest that Sunday as it headed down towards the barricades. “It was gridlocked with demonstrators,” he said.

Bloody Sunday: Derry awaits decision on possible murder trial Read more

“As I was coming up to Free Derry Corner I saw armoured cars and soldiers pushing up towards us. People were running and screaming as they felt the bullets overhead. When I got back to our house, my father told me: ‘Willy’s dead.’ I just broke down crying.

“He had been hit in the back. In the ambulance he had asked: ‘Am I going to die?’ Then he slipped into a coma. His spleen had been ruptured.

Facebook Twitter Pinterest Michael McKinney, whose brother William was killed, by the Bloody Sunday memorial in Derry. He said he wanted to see the soldiers responsible prosecuted. Photograph: Liam McBurney/PA

“I want to see the soldiers who shot him prosecuted. If not, I will be disappointed. I want the soldier responsible to go to prison. I don’t know how long for. The important thing is that charges are brought. These people went crazy. It’s taken so long. It’s been compounded by the British government protecting the soldiers and lying about what happened.”

Hegarty, 70, works at the Museum of Free Derry directly opposite the Bloody Sunday memorial. She was living in Canada when she heard that her younger brother, 17-year-old Kevin McElhinney, had been killed.

“I initially saw news reports that six gunmen and bombers had been shot,” she said. “I sighed with relief – I didn’t know any gunmen or bombers. The next morning an aunt rang and told me: ‘Kevin is dead’. He had been crawling away. He was hit in the backside and the bullet travelled up through his body. I flew back on the Monday night. On the flight from Toronto to Prestwick I was plotting how to avenge my brother’s death.

“In church the next day, I knelt forward and looked along the pew and saw my father. He was a beaten man. He was never the same again. And I thought: no one should go through that. The sense of revenge left me.

Facebook Twitter Pinterest Jean Hegarty, whose brother Kevin McElhinney was killed aged 17, works at the Museum of Free Derry. Photograph: Charles McQuillan/Getty Images

“I would hope there’s evidence to bring charges for his death. If a soldier commits a crime it should be followed through. I’m not sure I want them to serve a prison sentence. The Saville inquiry went a good way in declaring that those who were killed had been innocent.”

Kelly, 70, said he was “hopeful but also nervous and anxious” that the prosecution service would eventually deliver justice. “I want to see soldiers charged and convicted. I want to see them serve prison sentences.

“My younger brother, Michael, was 17. He would have been 64 had he lived. Those soldiers have to face the consequence of what they did. I believe they should get a life sentence. None of them have ever shown any remorse, not at the Saville inquiry or since.

“I was with Michael when he was shot. I went in the ambulance with him. I can still see him lying there after being shot. He was a young boy. His face turned grey and a sort of green colour. I was in the mortuary afterwards. There were nine or 10 bodies. It was pure carnage. My mother never got over the loss of her son.”

Facebook Twitter Pinterest John Kelly’s 17-year-old brother Michael was killed. He said he was ‘hopeful but also nervous and anxious’ for justice. Photograph: Liam McBurney/PA

Col Derek Wilford, who commanded the Parachute Regiment on Bloody Sunday, told BBC News on Wednesday that his former soldiers should not be prosecuted.

The 85-year-old retired officer said his men had been betrayed by the decision to launch a criminal investigation into their actions that day. “I was there,” he said. “We thought we were under attack and we remain convinced of that.”

On Tuesday the Ministry of Defence sent MPs a letter explaining the help and legal representation it was offering to “veterans in legacy cases”, specifically those who may face charges in relation to Bloody Sunday. It said: “We are committed to providing high-quality welfare and pastoral support to all those veterans affected by historic investigations.”

Where required, it said, “barristers, including senior counsel, will be instructed to represent individual veterans in any court proceedings that follow or to advise or to advise on specialist areas of laws as necessary.”

The paratroopers were not identified in the Saville inquiry but known only by a sequence of letters. That anonymity is expected to be continued in the PPS’s announcement. If they are brought to court, however, there is likely to be a legal battle over identification.

Paul O’Connor, director of the Pat Finucane Centre in Derry, which supports families who lost relatives in the Troubles, said it was likely that Northern Ireland legislation, which limits sentences for offences committed after 1973 to an upper limit of two years, would be backdated to 1966. That would ensure that any paratroopers, if convicted, would serve only relatively short sentences.

A more ambitious “statute of limitations”, which the Ministry of Defence has discussed in relation to other conflicts, has not yet materialised.

“Our understanding is that if prosecuted they would have to appear in court somewhere in the jurisdiction of Northern Ireland,” O’Connor said. “Two other paratroopers who were charged last year with murdering Joe McCann, an Official IRA leader in 1972, still enjoy anonymity.

“From 1970 on, soldiers had a de facto amnesty in Northern Ireland. Documents from the National Archives show there were discussions between the attorney general and the chiefs of staff where they made it quite clear they would do everything in their power to protect soldiers from prosecution.”