Just one soldier will face charges in relation to Bloody Sunday it has emerged.
Families of those who died march through the Bogside in Londonderry, Northern Ireland, ahead of an announcement over the prosecution of 17 former British soldiers and two former members of the Official IRA in connection with the events of Bloody Sunday in the city in January 1972.
A former British paratrooper has been charged for the killing of two unarmed protesters in Northern Ireland in 1972, in an incident that has become known as Bloody Sunday.
"In these circumstances the evidential test for prosecution is not met".
The PPS pored over more than 125,000 pages of evidence from Bloody Sunday in coming to their decision.
Police in the North opened their investigation into the killings after the 2010 Saville Report found that British troops opened fire on Bloody Sunday without issuing a warning.
It cost a quarter of a billion dollars and its conclusions, announced by British Prime Minister David Cameron in 2010, brought cheers from the people of Derry, in particular the victims' families.
The PPS found there was sufficient evidence to charge the ex-serviceman "Soldier F", but insufficient evidence to bring charges against 16 other former members of the 1st Battalion Parachute Regiment and two IRA suspects present on the day of the killings.
Director of Public Prosecutions for Northern Ireland, Stephen Herron said he was conscious relatives faced an "extremely hard day".More news: Stream PC games to Xbox One with new Wireless Display app
More news: USA prosecutors probing Facebook's data deals, New York Times says
More news: Google’s first public Android Q beta is now available for Pixel phones
Reflecting on his meeting with the families, the director added: "I am mindful that it has been a long road for the families to reach this point and today will be another extremely hard day for many of them".
A short internal military inquiry shortly after Bloody Sunday, known as the Widgery Report, concluded the soldiers had done nothing wrong.
"However, much of the material which was available for consideration by the Inquiry is not admissible in criminal proceedings, due to strict rules of evidence that apply".
"As prosecutors we are required to be wholly objective in our approach".
"We are making a summary of the reasons for our decisions available today to provide assurance to the public that our statutory responsibility was undertaken in this case with absolute integrity and impartiality, without fear or favour".
Irish Foreign Minister Simon Coveney said it was important that no one said anything to prejudice the process following Thursday's decision, adding that his thoughts were with all of the families.
She said: "I think of my brother every single day".
"If you have a family member and something like that happens to them. your brother, your poor dead brother is treated like he never existed, that he wasn't worth justice, what every one of us are entitled to".
According to RTÉ, the retired soldier is expected to robustly contest the charges.