A U.S. Border Patrol agent takes a selfie at the U.S.-Mexico border fence on April 30, 2016, near San Diego, California. On this day, five families, some of whose members lived in Mexico and others in the United States, were permitted to meet and embrace for three minutes each at a door in the fence, which the U.S. Border Patrol opened to celebrate Mexican Children's Day. It was only the third time that the fence, which separates San Diego from Tijuana, had been opened for families to briefly reunite. #

U.S. Border Control agents take undocumented immigrants into custody after capturing them crossing the Rio Grande from Mexico into Texas on August 18, 2016, near Sullivan City, Texas. #

The border fence stops at a hillside on the U.S.-Mexico border in Jacamba Hot Springs, California, on September 26, 2016. The border stretches almost 2,000 miles, much of it very remote, and fencing often stops due to geographical features, such as hills and rivers. #

Civilian paramilitary volunteer James, 24, with Arizona Border Recon (AZBR), stands near the U.S.-Mexico border on November 16, 2016, in Pima County, Arizona. The college student said he felt it was his duty to help protect the nation's borders. "There's evil going on here," he said. AZBR is made up mostly of former U.S. military servicemen, and stages reconnaissance and surveillance operations against drug and human smugglers in remote border areas. The group claims up to 200 volunteers and does not consider itself a militia, but rather a group of citizens supplementing U.S. Border Patrol efforts to control illegal border activity. #

Power lines run near the U.S.-Mexico border at sunset in Columbia, New Mexico, on September 30, 2016. The New Mexican stretch of the border is some of the most remote and uninhabited of the entire 2,000-mile boundary between the two countries. #

Mexico is seen over the U.S.-Mexico border fence at Imperial Sand Dunes on November 17, 2016, near Felicity, California. The 15-foot border fence there, also known as the "floating fence," sits atop the dunes and moves with the shifting sands. Border Patrol agents say they catch groups of illegal immigrants and drug smugglers crossing in from Mexico there daily, despite the forbidding terrain. #

Trevis Hairston, a death investigator, moves a corpse in the morgue of the Pima County Medical Examiner in Tucson, Arizona, on September 29, 2016. Hundreds of undocumented immigrants die every year, most from dehydration, in the desert while crossing illegally from Mexico into the United States. Forensic anthropologists study personal effects and bodily remains in an effort to identify the bodies and reunite them with loved ones. #

In Guatemala City, Guatemala, homes climb up the hillside in the Limonada slum on February 8, 2017. Grinding poverty and high crime continue to drive emigration from Guatemala to the United States, even as the Trump administration moves to tighten border security. #

Guatemalan immigrants deported from the United States arrive on an ICE deportation flight on February 9, 2017, in Guatemala City, Guatemala. The charter jet, carrying 135 deportees, arrived from Texas, where U.S. Border Patrol agents catch the largest number of illegal immigrants crossing into the United States, many of them from Central America. #

A neighborhood-watch volunteer stands guard on her street on February 9, 2017, in Peronia, Guatemala. Residents of Peronia, south of Guatemala City, organized to secure their community after 10 of their neighbors were killed in January, they say, for refusing to pay extortion money to gangs. Armed with machetes and sticks, residents take turns each night, barring strangers' entry into their neighborhoods. Violence and poverty continue to drive emigration from Central America to the United States. #

Maria Isabel Luna, 75, wears an American flag-themed towel for warmth over her traditional Mayan dress while working at a vegetable market on February 11, 2017, in Almolonga, Guatemala. She said that two of her family members work as immigrant laborers in Los Angeles. The Mayan town in the western highlands district of Quetzaltenango has surged in prosperity in recent years with high-productivity vegetable farming, exporting much of its excess crops to neighboring El Salvador. The town has been called the "Vegetable Basket of the Americas." Many locals attribute the town's change in fortune to the rapid growth of the evangelical Christian faith in the area, while others credit the increased use of pesticide farming. Regardless, the strong local economy will be key to maintaining the town's prosperity if the Trump administration follows through on curtailing remittance money sent back from undocumented immigrants in the U.S. to their families in Guatemala. #

A U.S. Customs and Border Protection helicopter pilot searches for undocumented immigrants while flying a night patrol with night-vision goggles over the U.S.-Mexico border near La Grulla, Texas, on March 15, 2017. #

A construction crew works on a new section of the U.S.-Mexico border fence on August 1, 2017, as seen from a U.S. Customs and Border Protection helicopter near Sunland Park, New Mexico. #

A group of undocumented immigrants wades across the Rio Grande at the U.S.-Mexico border in Roma, Texas, on March 14, 2017. U.S. Border Patrol agents had intercepted them on the Texas side of the river and pushed them back into Mexico. #

New U.S. Border Patrol agents attend a Spanish-language class at the Border Patrol Academy on August 2, 2017, in Artesia, New Mexico. All new Border Patrol agents attend the academy in New Mexico before assuming their posts, mostly along the U.S.-Mexico border. President Trump pledged to add an additional 5,000 agents to the existing Border Patrol force of more than 21,000 as part of his border-security policy. #

A U.S. Border Patrol instructor yells at a new trainee upon her initial arrival with fellow agents to the U.S. Border Patrol Academy in Artesia, New Mexico. on August 2, 2017. #

Agent Fuentes, 32, stands for a portrait while attending the U.S. Border Patrol Academy on August 3, 2017, in Artesia, New Mexico. Fuentes said that before joining the Border Patrol he had been a nursing student. #

In San Pedro Sula, Honduras, a girl looks from the modest yard of her family's one-room home in an impoverished neighborhood on August 18, 2017. Honduras, consistently ranked as one of the poorest nations in the Western Hemisphere, also has one of the highest murder rates in the world. The poverty and violence have been major elements driving emigration to the United States. #

Sonia Morales massages the back of her son Jose Issac Morales, 11, at the door of their one-room home on August 20, 2017, in San Pedro Sula, Honduras. The mother of three said that her son's spinal deformation began at age four, but she has never been able to afford the $6,000 surgery to correct his spinal condition. The boy's father, Issac Morales, 30, said he tried to emigrate to the U.S. in 2016 to work and send money home, but was picked up by U.S. Border Patrol officers in the Arizona desert and deported back to Honduras. #

Local Barrio 18 gang leader "El Mortal," 18, poses for a photo in San Pedro Sula, Honduras, on August 19, 2017. He said he has been a gang member since he was 10 years old. In Honduras, rival gangs, including Barrio 18 and MS-13, tightly control territory, earning money from extortion and drug trafficking. San Pedro Sula has one of the highest rates in the world for violence and homicide rates, most of it gang-related, for a populace not at war. #

U.S. Border Patrol agents question undocumented immigrant families at the U.S.-Mexico border fence while taking them into custody on February 21, 2018, near McAllen, Texas. A group of men, women, and children from Central America were picked up after crossing the Rio Grande into Texas, seeking political asylum in the United States. #

A suspected undocumented immigrant swims across the Rio Grande into Mexico while evading capture by U.S. border agents on February 21, 2018, near McAllen, Texas. Air interdiction agents from U.S. Air and Marine Operations, U.S. Border Patrol agents, and Texas state troopers conducted a high-speed chase after a pickup failed to yield and then raced to the Mexican border. The vehicle crashed into a tree on the Texas side of the Rio Grande, and the three occupants evaded arrest before swimming into Mexico. #

Central American immigrants turn themselves in to U.S. Border Patrol agents near McAllen, Texas, on February 22, 2018. Thousands of Central American families continue to enter the U.S., most seeking political asylum from violence in their home countries. #

Central American immigrants turn themselves in to Border Patrol agents near McAllen, Texas, on February 22, 2018. The girl, 14, from Honduras, said that she picked up the puppy in Reynosa, Mexico, during her journey. #

Undocumented immigrants are taken into custody by U.S. Border Patrol agents on February 22, 2018, near McAllen, Texas. Spotted by infrared cameras from a surveillance tower, the group had crossed from Mexico into Texas only moments before. #

A U.S. Border Patrol agent watches over a group of undocumented immigrants on February 23, 2018, in McAllen, Texas. The agents captured the group of Central American immigrants shortly after they rafted across the border from Mexico into Texas. #

In Hermosillo, Mexico, immigrants, most of them from Central America, walk to a soup kitchen after traveling by freight train on their journey towards the U.S.-Mexico border on April 21, 2018. About 600 immigrants were part of a caravan that crossed into Mexico almost a month earlier. The caravan was within days of reaching the border. Traveling together, many atop freight trains known as the "beast," they have sought safety in numbers on the dangerous journey. Along the way, they have received an outpouring of help from local charities, the Red Cross, private citizens, and even the Mexican government. #

A Honduran asylum seeker, Daniel Once, 2, arrives at an immigrant shelter with his family on April 25, 2018, in Tijuana, Mexico. More than 300 immigrants, the remnants of a caravan of Central Americans that began almost a month ago, were arriving in Tijuana on the last leg of their journey north within Mexico. They planned to seek political asylum at the U.S. border the following weekend. #

On June 12, 2018, Central American asylum seekers wait as U.S. Border Control agents take groups of them into custody near McAllen, Texas. The families were then sent to a CBP processing center for possible separation. U.S. Border Control authorities are executing the Trump administration's zero-tolerance policy towards undocumented immigrants. U.S. Attorney General Jeff Sessions also said that domestic and gang violence in immigrants' countries of origin would no longer qualify them for political-asylum status. #

U.S. Border Patrol agents take a father and son from Honduras into custody near the U.S.-Mexico border near Mission, Texas, on June 12, 2018. The asylum seekers were then sent to a CBP processing center for possible separation. #

An undocumented immigrant is given water by U.S. Border Patrol agents after she was apprehended in a sugarcane field near the U.S.-Mexico Border on June 12, 2018, near Mission, Texas. #

A U.S. Border Patrol spotlight shines on a terrified mother and son from Honduras as they are found in the dark near the U.S.-Mexico border on June 12, 2018, in McAllen, Texas. The asylum seekers had rafted across the Rio Grande from Mexico and had become lost in the woods. They were then detained by Border Patrol agents and sent to a processing center for possible separation. #

A Honduran mother removes her two-year-old daughter's shoelaces, as required by U.S. Border Patrol agents, after being detained near the U.S.-Mexico border near McAllen, Texas, on June 12, 2018. #

A Honduran mother holds her two-year-old as U.S. Border Patrol agents review their papers near the U.S.-Mexico border on June 12, 2018. The asylum seekers had rafted across the Rio Grande from Mexico and were detained by U.S. Border Patrol agents before being sent to a processing center for possible separation. #

A two-year-old Honduran asylum seeker cries as her mother is searched and detained near the U.S.-Mexico border on June 12, 2018 in McAllen, Texas. The mother set her down to allow the search to take place, and the girl immediately began screaming. Then, according to an interview with Moore by the Washington Post reporter Avi Selkan, "the woman picked up her daughter, they walked into the van, the van drove away, and Moore never saw them again." A June 20 article from The Daily Beast says they spoke with a U.S. Customs and Border Protection spokesperson, who told them that this particular mother and child were not separated during processing. #