The incident was little-known outside Korea until publication of an Associated Press (AP) story in 1999 in which veterans of the U.S. Army unit involved, the 7th Cavalry Regiment, corroborated survivors' accounts.

[8][9] On the night of July 25, that division's 2nd Battalion, 7th Cavalry Regiment,[nb 1] hearing of an enemy breakthrough, fled rearward from its forward positions, to be reorganized the next morning, digging in near the village of Nogeun-ri (also romanized as No Gun Ri), 100 miles southeast of Seoul.

They continued down the road, were stopped by American troops at a roadblock near No Gun Ri, and were ordered onto the parallel railroad tracks, where U.S. soldiers searched them and their belongings, confiscating knives and other items.

[16] "Children were screaming in fear and adults were praying for their lives, and the whole time they never stopped shooting," said survivor Park Sun-yong, whose 4-year-old son and 2-year-old daughter were killed, while she was badly wounded.

Two communications specialists, Larry Levine and James Crume, said they remembered orders to fire on the refugees coming to the 2nd Battalion command post from a higher level, probably from 1st Cavalry Division.

[21][24] In the earliest published accounts of the killings, in August and September 1950, two North Korean journalists with the advancing northern troops reported finding an estimated 400 bodies in the No Gun Ri area, including 200 seen in one tunnel.

[30][31] Information about the refugee killings reached the U.S. command in Korea and the Pentagon by late August 1950, in the form of a captured and translated North Korean military document, which reported the discovery of the massacre.

[32] A South Korean agent for the U.S. counterintelligence command confirmed that account with local villagers weeks later, when U.S. troops moved back through the area, the ex-agent told U.S. investigators in 2000.

[3]: 179 [5] On April 28, 1998, the Seoul government committee made a final ruling against the No Gun Ri survivors, citing the long-ago expiration of a five-year statute of limitations.

In March 1999, the Army told the U.S. council that it had looked into the No Gun Ri allegations, and "found no information to substantiate the claim" in the operational records of the 1st Cavalry Division and other frontline units.

[12]: 148 [11]: 275–76 Months before the Army's private correspondence with the church group, Associated Press reporters, researching those same 1950 operational records, found orders to shoot South Korean civilians.

The U.S.-based news agency, which reported the rejection of the survivors' claim in April 1998, had begun investigating the No Gun Ri allegations earlier that year, trying to identify Army units possibly involved, and to track down their ex-soldiers.

[11]: 269–84  On September 29, 1999, after a year of internal struggle over releasing the article,[41] the AP published its investigative report on the massacre, based on the accounts of 24 No Gun Ri survivors, corroborated by a dozen 7th Cavalry Regiment veterans.

The journalists' research into declassified military documents at the U.S. National Archives uncovered recorded instructions in late July 1950 that front-line units shoot South Korean refugees approaching their positions.

[44] A U.S. Navy document later emerged in which pilots from the aircraft carrier USS Valley Forge reported that the Army had told them to attack any groups of more than eight people in South Korea.

[14][55] In the ensuing 15-month probes, conducted by the U.S. Army inspector general's office and Seoul's defense ministry, interrogators interviewed or obtained statements from some 200 U.S. veterans and 75 Koreans.

[33]: 14 [57] The South Korean report said five former Air Force pilots told U.S. interrogators that they were directed to strafe civilians during this period, and 17 veterans of the 7th Cavalry testified that they believed there were orders to shoot the No Gun Ri refugees.

[4]: 120, 157, 161 fn27 [23]: 596 Regarding the aerial imagery that the U.S. report said suggested a lower death toll, the South Korean investigators, drawing on accounts from survivors and area residents, said at least 62 bodies had been taken away by relatives or buried in soldiers' abandoned foxholes in the first days after the killings, and others remained inside one underpass tunnel, under thin layers of dirt, out of sight of airborne cameras and awaiting later burial in mass graves.

In addition, South Korean military specialists questioned the U.S. reconnaissance photos, pointing out irregularities, including the fact that the No Gun Ri frames had been spliced into the roll of film, raising the possibility they were not, as claimed, from August 6, 1950, eight days after the killings.[4]: App.

"[14][68] In a letter to Defense Secretary Cohen, another U.S. adviser, retired Marine general Bernard E. Trainor, expressed sympathy with the hard-pressed U.S. troops of 1950, but said the killings were unjustified, and that "the American command was responsible for the loss of innocent civilian life in or around No-Gun-Ri.

[nb 12] In addition, interview transcripts obtained through Freedom of Information Act requests showed that the Army had not reported repeated testimony from ex-soldiers that, as one put it, "the word I heard was 'Kill everybody from 6 to 60'" during their early days in Korea.

[69] American lawyers for the No Gun Ri survivors rejected that rationale, asserting that whether 7th Cavalry troops acted under formal orders or not, "the massacre of civilian refugees, mainly the elderly, women and children, was in and of itself a clear violation of international law for which the United States is liable under the doctrine of command responsibility and must pay compensation".

Writing to the Army inspector general's office in May 2001, the lawyers also pointed out that numerous orders were issued at the war front to shoot civilians, and said the U.S. military's self-investigation – "allowing enforcement to be subject to the unbridled discretion of the alleged perpetrator" – was an ultimate violation of victims' rights.

But Baik also contended any mass killing of noncombatants remained a crime under “customary international law.”[36]: 473–477  American soldiers sent to Korea in 1950 were issued a booklet telling them the Hague treaty forbade targeting civilians.

Meeting with South Korean officials in 2001, the survivors asked that their government seek action at the International Court of Justice at The Hague, and in U.N. human rights forums, but were rebuffed.

[78]: 267, 306  In 2002, a spokesman for South Korea's then-governing party called for a new U.S. inquiry,[79] but the Defense Ministry later warned the National Assembly that a reopened probe might damage U.S.–South Korean relations.

[80] In a 2015 book, David Straub, U.S. Embassy political chief during the No Gun Ri investigation, wrote that meeting the survivors' demands would have set an undesirable precedent for similar cases from 1950 Korea.

[84][85] After the United States refused to offer compensation and the survivors rejected the plan for a war memorial and scholarship fund, South Korea's National Assembly on February 9, 2004, adopted a "Special Act on the Review and Restoration of Honor for the No Gun Ri Victims".

[89] In the United States and Britain, No Gun Ri was a central or secondary theme in six English-language novels, including the U.S. National Book Award finalist Lark & Termite of 2009, by Jayne Anne Phillips, the James Bond thriller Trigger Mortis of 2015, by British author Anthony Horowitz.

[90] The 1999 No Gun Ri articles prompted hundreds of South Koreans to come forward to report other alleged incidents of large-scale civilian killings by the U.S. military in 1950–1951, mostly in the form of air attacks.