One former British soldier is to be charged with the murders of two men and the attempted murders of four others over the Bloody Sunday shootings.
There was insufficient evidence to provide a reasonable prospect of conviction for the other 16 former soldiers, the Public Prosecution Service said.
Families gathered outside The Museum of Free Derry, yards from where the killings took place 47 years ago, and marched together to the city centre to hear the decision.
Thirteen people were killed and 15 others injured on 30 January 1972 when troops of the 1st Battalion of the Parachute Regiment fired on demonstrators during a civil rights march in Derry.
An image of a Catholic priest waving a blood-stained handkerchief as he tried to help a victim to safety was seen around the world.
The troops were sent into the Bogside nationalist housing estate to deal with riots which followed the march defying a ban on public processions.
In 2010, a public inquiry under Lord Saville – ordered by former prime minister Tony Blair in 1998 – concluded the killings to have been “unjustified and unjustifiable”.
The investigation, which lasted 12 years and cost around £195m, dismissed suggestions the dead had been armed with guns and nail bombs.
It also criticised the decision to send soldiers into the estate in vehicles.
The paratroopers were not identified by the Saville inquiry. They were known only by a sequence of letters.
The outcome of the inquiry opened up the possibility of criminal charges being made against the troops involved.
Then prime minister David Cameron also apologised to the families of the victims in a statement in the House of Commons.
An investigation by the Police Service of Northern Ireland (PSNI) followed the inquiry and files on 18 soldiers were submitted to prosecutors in 2016 and 2017 for consideration. One veteran has since died.
Four other soldiers included in the Saville report died before police had completed their investigation.
Papers before prosecutors included 668 witness statements and numerous photos, video and audio evidence.