After Eduardo, a teenager from Guatemala, and his two younger cousins were detained while crossing into Arizona last year, Border Patrol officials accused him of trafficking the children, he said.

Then 16, he was separated from his cousins and taken into a small room in a detention facility, where an officer threatened to put him in jail for 10 years and send him back to Central America.

Then, he said, the officer slapped him across the face.

“My head hurt and it burned for a good while. I thought this country was decent but after this happened, I felt horrible,” said Eduardo, according to a report published on Friday by Americans for Immigrant Justice, a nonprofit legal organization in Miami. “I would never wish this on another kid that passes through there.”

The 70-page report — “Do My Rights Matter? The Mistreatment of Unaccompanied Children in CBP Custody” — draws upon interviews in 2019 with nearly 9,500 minors, or about 1 in 8 of all those who were apprehended and detained by U.S. Customs and Border Protection last year.

Of the children screened, 895 — nearly 1 in 10 — said they had been verbally abused by CBP officers, while 147 said they had been subjected to physical abuse.

More than half of all children said they stayed in CBP custody longer than three days, in violation of a long-standing legal settlement, and just over 40 percent reported a lack of adequate food or water during their detention. It is unclear if the responses collected by Americans for Immigrant Justice resulted in any formal complaints to CBP.

A spokesperson for the federal agency said in a statement to The Washington Post that its officers are expected to adhere to a lengthy set of standards while interacting with detainees.

“CBP treats those in our custody with dignity and respect and provides multiple avenues to report any misconduct,” the spokesperson said. “We take all allegations seriously and investigate all formal complaints.”

Many of the accounts laid out in the AI Justice report — including noisy and crowded facilities, frigid temperatures, and frozen, rotten or otherwise inadequate meals — reflect common complaints by immigration advocates. For years, groups like AI Justice have sounded alarms about CBP facilities along the border, which, depending on their design, have been derided by migrants as “la hielera” (“the icebox”) or “la perrera” (“the dog kennel”) due to the cold, cramped conditions inside.

“This isn’t new,” Jennifer Anzardo Valdes, one of the report’s authors and the director of the children’s legal program at AI Justice, said in an interview with The Post. “We have been documenting CBP abuse for years, and they have done nothing to really change their treatment of the children in the facilities.”

The Trump administration’s past approaches to migrant children sparked fresh outrage this month when legal filings revealed that the parents of more than 500 children separated at the border have yet to be located.

President Trump has seemingly grown frustrated at the backlash regarding “kids in cages.” During the final presidential debate last week, he pointed out that it was President Barack Obama who constructed these processing centers. Trump defended how children were treated while inside.

“They are so well taken care of,” he said. “They’re in facilities that were so clean.”

As The Post’s Nick Miroff reported, the Obama administration did in fact make changes in 2014 to its detention centers — which had been designed for single adult men — to handle an unprecedented number of Central American families crossing the border. But it was Trump’s “zero tolerance” policy four years later that led to the facilities being used to house children separated from their parents, as a way to discourage migrants from crossing the border.

Even after that policy was reversed in 2018, six weeks after it was first officially rolled out, unaccompanied minors continued entering the United States. Last year, more than 76,000 were detained by CBP, a new high.

In its new report, Americans for Immigrant Justice described in the children’s experiences in the facilities as “horrific.”

“Although many of these children come seeking refuge,” the organization’s report said, “they often suffer an inhumane and cruel experience in their first encounter with the U.S. government that leads to further trauma.”

By far the most common complaint among the children screened was that it was too cold inside the detention centers, where they are generally given thin Mylar blankets to keep warm.

One 17-year-old mother from Honduras, referred to in the report only as Elena, said she had been shackled by CBP officers and told that she would never again see her son, who has asthma. When she asked for another blanket for him, they yelled at her, she said, according to the report.

“They didn’t treat me well,” she said. “One of the officers spoke really badly to me whenever I asked him for things.”

A CBP spokesperson said in a statement that facilities are kept at “a reasonable and comfortable range for both detainees and officers,” or somewhere between 68 and 74 degrees Fahrenheit along the U.S.-Mexico border. The spokesperson added that supervisors check the temperature of every cell before every shift, and that officers are banned from using temperature controls “in a punitive manner.”

A federal court decree maintains that the government can only detain migrant children without their parents for a period of up to 72 hours before passing them on to a network of shelters and foster care. But the new report found that the average stay in CBP custody of children the group interviewed was 10 days, or more than three times the limit.

From CBP’s facilities, unaccompanied migrant children are transferred to the care of the Office of Refugee Resettlement, which operates a wide range of shelters and group and foster homes, often with contractors. A tent city in Tornillo, Tex., as well as a massive detention center in Homestead, Fla., both received significant scrutiny from the public in 2019 as they housed thousands of children at a time.

A 17-year-old Nicaraguan, referred to in the report only as Juan, said he was erroneously placed in adult detention centers by officials who insisted he was not a minor and handcuffed him when he tried to confront them about their treatment. Altogether, he spent 58 days in adult detention and waited more than 100 days before being released to a family member in the United States.

The CBP spokesperson said that “every effort is made to hold detainees for the least amount of time required,” but noted that “logistics and changing demographics” meant that the agency was not able to keep all children in its custody for 72 hours or less.

“However, that is still the goal and the agency, working with partners, is still doing everything it can to move people out of temporary CBP holding facilities,” the statement said.