Photographer John Moore tells PEOPLE that "after I shot this picture, I had to stop and take a few deep breaths"
Photographer John Moore was hiding with border patrol agents along the northern banks of the Rio Grande River on June 12 when he saw raft-loads of asylum seekers headed for the Texas shore from Mexico.
Upon landing, the two dozen people, mostly women and children, trekked through the woods toward a road. Recalls Moore: “I could hear a boy crying in the distance.”
Quickly, the Pulitzer Prize-winning photographer for Getty Images jumped into a truck with one of the border patrol agents and rushed to meet the immigrants.
“As we pulled up there was one little boy, about 10 or 12, who was very agitated,” Moore tells PEOPLE. “I tried to calm him down a little and showed him some pictures on the back of my camera of the river.”
But it would be Moore‘s heartbreaking photo of another child in the group, a two-year-old girl from Honduras wailing as an agent inspected her mother with gloved hands, that has become a symbol of the cruelty amid Donald Trump’s new policy of separating asylum-seeking parents from their children.
Moore has spent years capturing emotionally wrenching images of the men, women and children attempting to come to America through Mexico. He’s documented their hardscrabble lives in Central America and along the route to the US-Mexico border, and earlier this year published a book of his work: Undocumented: Immigration and the Militarization of the United States-Mexico Border.
On the evening he took that viral photo, he felt a dread over what would soon unfold.
“It felt very different,” he says. “I knew many of these parents and children would be separated later. They did not know what was about to happen to them. But I did.”
It was close to 11 p.m. when border patrol agents began taking names and documents to register the immigrants. “Although they had come such a long distance,” Moore says, “they were still afraid.”
The border patrol agent with Moore joked with the children, “trying to allay their fears, trying to calm them, not terrify the children.”
Moore photographed several kids huddled with their parents. And then he saw a woman holding the two-year-old girl.
“She was clinging to her mother and she did not want to be set down,” he says. “She was feeling anxious.”
He snapped a photo of the woman breastfeeding the girl. The mother told Moore she was from Honduras and traveling for a month through Mexico — a distance of over 1,500 miles.
“That journey is very dangerous for these people,” Moore says. “They are prey to criminal gangs, the elements outside, and it’s a very tough journey.”
When it was the mother’s turn to be searched, a federal agent asked her to put the little girl down so a rubber-gloved female worker could perform a pat-down.
“The mother hesitated and then set down the little girl and the child immediately started crying,” Moore recalls. “As a father, it was very emotional for me just to hear those cries. When I saw this little girl break down in tears I wanted to comfort this child.
“But as a photojournalist we sometimes have to keep photographing when things are hard,” he continues. “And tell a story that people would never see.”
Moore had just a few seconds. He crouched six feet from the girl as she looked up at her mother, screaming. He snapped seven shots while the mother stared straight ahead, her hands spread out on the border patrol vehicle. She was quiet. Stoic, says Moore.
“It was very dark and hard to focus,” he remembers, “and it all happened very quickly.”
The iconic photograph of the little girl crying was the last photo Moore took that night. “And after I shot this picture, I had to stop and take a few deep breaths,” he says. “It was very emotional for me.”
Afterwards, Moore says agents led the mother and child into a van, and they were taken away to a processing center, away from photographers’ lenses and public view.
“I was anxious and sad,” he says. “It was hard to see.”
“I wish I knew what happened to that mother and daughter,” he says. “It touched me at that moment, and I still think about that moment often.” (On Wednesday, The Daily Beast reported that a spokesman for U.S. Customs and Border Protection said “the mother and daughter were not separated.” The spokesman also told the outlet that the girl and her mom were expected to stay together at a detention center as their case goes through federal court.)
Moore has two daughters, 11 and 13, and a three-year-old son. “I would be hard for any parent,” he says, “to imagine the stress of such a situation.”
That night, Moore returned to his hotel in Texas, and to his Connecticut home and three children the next day.
Soon the photo would go viral. And like millions of others who see the image, says Moore, “it makes me cry too.”