(CNN)A year before the Trump administration's "zero-tolerance" policy resulted in more than 2,300 children being separated from their families at the border in a mere five-week period, a ninth-grader in McAllen, Texas, was taken from his mother.

He was riding in a car with friends last spring when the car was pulled over. The teenager, brought illegally to the country by his mother as a baby, was unable to show identification. Police called immigration officials, who arrested the boy and sent him to a shelter for unaccompanied migrant children.

John Doe 2, as he is referred to in current legal filings challenging his detainment, became one of thousands caught in a network of shelters and higher-security facilities that house undocumented minors, now gaining attention as newly separated children have been streaming in.

Immigration attorneys working directly with migrant children say some of these facilities provide the best care they can, given the circumstances. And a huge shelter in Brownsville, Texas, which opened its doors for a media tour last week, appeared to be clean and well-staffed at the time.