BAGHDAD, 23 May 2004 — The scandal at Abu Ghraib prison was first exposed not by a digital photograph but by a letter. In December 2003, a woman prisoner inside the jail west of Baghdad managed to smuggle out a note. Its contents were so shocking that, at first, Amal Kadham Swadi and the other Iraqi women lawyers who had been trying to gain access to the US jail found them hard to believe. The note claimed that US guards had been raping women detainees, who were, and are, in a small minority at Abu Ghraib. Several of the women were now pregnant, it added. The women had been forced to strip naked in front of men, it said. The note urged the Iraqi resistance to bomb the jail to spare the women further shame.

On the morning of November 19, 2005, a squad of Marines was travelling in four Humvees down a road in the town of Haditha, Iraq, when their convoy hit an I.E.D. The blast killed one Marine, Lance Corporal Miguel Terrazas, and injured two others. What followed would spark one of the largest war-crime investigations in the history of the United States.

During the next several hours, Marines killed twenty-four Iraqi men, women, and children. Near the site of the explosion, they shot five men who had been driving to a college in Baghdad. They entered three nearby homes and killed nearly everyone inside. The youngest victim was a three-year-old girl. The oldest was a seventy-six-year-old man. The Marines would later claim that they were fighting insurgents that day, but the dead were all civilians.

After the killing was over, two other Marines set off to document the aftermath. Lance Corporal Ryan Briones brought his Olympus digital camera. Lance Corporal Andrew Wright had a red Sharpie marker.

Briones and Wright went from site to site, marking bodies with numbers and then photographing them. Other Marines, including one who worked in intelligence, also photographed the scene. By the time they were done, they had made a collection of photographs that would be the most powerful evidence against their fellow-Marines.

The impact of an alleged war crime is often directly related to the horror of the images that end up in the hands of the public. The abuse of detainees at Abu Ghraib prison became an international scandal when graphic photos were published. The Haditha killings had no similar moment. A few of the images that the Marines had made ended up in the public domain, but most have never been released.

In an oral-history interview for the Marine Corps, in 2014, General Michael Hagee, who was the commandant of the Marine Corps at the time of the Haditha killings, bragged about keeping the Haditha photos secret.

“The press never got them, unlike Abu Ghraib,” Hagee said.

The interviewer, Fred Allison, a Marine Corps historian, interjected, “The pictures. They got the pictures. That was what was so bad about Abu Ghraib.”

“Yes,” Hagee replied. “And I learned from that.” He said, “Those pictures today have still not been seen. And so, I’m quite proud of that.”