More than a year after the Trump administration ended a controversial policy that led to hundreds of family separations, as many as five migrant children per day continue to be separated from their parents at the U.S.-Mexico border, according to federal data gathered by an immigrant advocacy group.

The data, which the American Immigration Council and other immigrant advocacy groups requested from the U.S. Department of Health and Human Services, shows that almost 400 children were separated from their parents between June 2018 — when the Trump administration ended its controversial zero tolerance policy — and March 2019.

That number jumped to more than 700 children by May, according to data the government provided to the American Civil Liberties Union, which is litigating the family separation crisis in federal court.

The Tribune's reporting for this project is supported by the Pulitzer Center.

Despite the executive order that President Donald Trump signed in June 2018 to end zero tolerance — which directed immigration officials to file charges against all adults who crossed the border illegally — advocates say adult migrants continue to be separated from children for reasons that are increasingly vague and difficult to corroborate.

Kathryn Shepherd, an attorney with the American Immigration Council, said separating family members at the U.S. border makes it difficult for lawyers and advocates get the full picture of why migrants flee their countries — details that are key to the asylum filing process.

“It shatters the process,” Shepherd said. “It’s really catastrophic for the individual, not just in terms of their emotional and physical well-being but also their ability to access the legal process.”

ProPublica reported that a 36-year-old Salvadoran man named Carlos was separated from his two children in South Texas last November — five months after Trump signed the executive order — when federal officials accused him of being a member of the MS-13 gang. Carlos told ProPublica that he presented evidence from the Ministry of Justice in El Salvador certifying that he had no criminal record, but federal agents, using a controversial gang database run by foreign governments, arrested him anyway.

According to the American Immigration Council’s data, 65% of children who are separated from their parents are removed because of a parent’s gang affiliation or criminal history. But lawyers and advocates say agents are relying on minor crimes, flimsy evidence and unverified allegations of gang affiliation to justify the continued separations of parents and children.

Children, in the meantime, are placed in federal shelters or with foster parents until they can be reunited with their parents or connected with a sponsor, usually a legal guardian or another family member. On average, children spend 45 days or less in federal shelters, according to the federal Office of Refugee Resettlement.

Federal law requires that unaccompanied minors be released to legal guardians. Alhough many migrant children arrive at the border with grandparents, aunts, uncles, siblings, cousins or step-parents, the government only considers a parent and child to be a legal family unit.

“They may have been raised by an uncle or an auntie, but they're not the legal guardian,” state Sen. Pete Flores, R-Pleasanton, said in a recent interview with The Texas Tribune.

"We don't want these children to fall into human traffickers or anything like that, but we want to make sure that the process to get them out goes as quickly as possible,” Flores added. “The detective work is awesome, really.”

Flores’ Senate District 19 stretches northwest from San Antonio to the Texas-Mexico border, covering many of the cities — like Del Rio, Eagle Pass and Carrizo Springs — that have been forced to respond to the surge of migrants crossing into the United States.

On Monday, he toured the facility that HHS set up in Carrizo Springs for unaccompanied minors and called the operation “first class,” highlighting the resources available to the few hundred 13- to 17-year-olds housed there so far — nurses, teachers, dorms separated by gender and age, air conditioning.

"Truly, the Border Patrol and the structure is overwhelmed,” Flores said. “I'm very pleased that this type of facility is there for them, and for others, and that it's not a detriment to the community or a threat to the community.”