Families mourning fathers and sons killed by British soldiers on the "Bloody Sunday" have long battled to prove their relatives' innocence and still hope to see justice served.

After British paratroopers opened fire on protesters on January 30, 1972, in Londonderry, Northern Ireland, it took 38 years for the 13 civilians shot dead to be recognized as innocent.

An initial report exonerated the soldiers, claiming the protesters had been infiltrated by Irish Republican Army (IRA) paramilitaries.

Victims' relatives derided the report by English judge John Widgery, published just three months after the killings.

John Kelly, whose brother Michael was killed, slammed the inquiry as "set up by the British government to tell lies about our people."

He launched a campaign for a new investigation, which finally took place in 1998.

The 12-year investigation, costing nearly £200 million ($420 million at current rates), was led by another senior judge, Mark Saville, and was the longest and most costly in British history.

It established that the victims were not armed and that the armed forces had given a misleading account of the events.

The then-Prime Minister, David Cameron, issued an official apology for the killings, calling them "both unjustified and unjustifiable."

Prosecutions halted, why?

The Saville report heavily criticized Lieutenant Colonel Derek Wilford, the commander of the troops involved, for sending soldiers into the area and disobeying orders.

He rejected the report's conclusions.

"We thought in fact that we were under attack. And we will remain convinced of that, actually, until the end of our days," he told the BBC in an interview in 2019.

Earlier that year, the Public Prosecution Service Northern Ireland charged a British ex-paratrooper known only as Soldier F with the murder of two people on "Bloody Sunday" and the attempted murder of four others.

But in July 2021, it announced the prosecution was to be halted.

It also opted not to prosecute another former soldier, known as Soldier B, for the murder of a 15-year-old boy who was killed with two bullets in the head in July 1972, also in Londonderry.

"No right to call itself a democracy"

The decision angered victims' families, and Michael McKinney, whose brother William was shot in the back, is seeking a judicial review of the Soldier F case.

The British government last year presented a controversial bill to parliament to prevent "vexatious" criminal prosecutions over alleged past crimes in the three-decade "Troubles" over British rule in Northern Ireland.

Critics condemned it as an effective amnesty for both soldiers and ex-paramilitaries.

Kate Nash, whose brother William Nash was also killed on "Bloody Sunday", has condemned the call to halt prosecutions, saying a country "has no right to call itself a democracy after putting anybody above the law."