Rick Jervis

USA TODAY

MISSION, Texas – A group of around 250 immigrants, mostly children, trotted across the U.S. border near the Anzalduas International Bridge here earlier this month and climbed atop a river levee.

Then, instead of sneaking around Border Patrol checkpoints or cramming into vans for safe houses farther north, the group did something peculiar for those crossing illegally into the USA: They squatted on the levee and awaited their arrest.

The group was part of the recent surge of unaccompanied minors who are streaming into this hot, flat stretch of South Texas, overwhelming Border Patrol facilities and sparking heated debate in Washington over what's causing the crisis and how to handle it.

One key difference the recent arrivals are displaying from their predecessors: They're not bothering to sneak deeper into Texas, opting instead to turn themselves in and allow U.S. policy toward immigrant youth decide their fate, said Chris Cabrera, a McAllen-based Border Patrol agent and vice president of the local chapter of the National Border Patrol Council.

"We're seeing record numbers of children coming across," he said. "We're dealing with so many of them turning themselves in that it makes it hard for our agents to focus on anything else."

The number of immigrant children served by the Office of Refugee Resettlement, which is responsible for the youth, has soared from around 7,000 to 8,000 a year earlier this decade to 13,625 in fiscal year 2012 and 24,668 last fiscal year, according to the office. So far this year, the agency has counted more than 42,000.

The children are crossing over from Mexico but are predominantly from Central American countries, such as Honduras, El Salvador and Guatemala. On Friday, Vice President Joe Biden is expected to meet with Guatemalan President Otto Perez Molina, along with Salvadoran and Honduran officials, in Guatemala to discuss the crisis.

Administration officials have said violence and economic hardship in those countries are prompting the children to seek a better life in the USA. Some lawmakers, however, argue the youths – and the smuggling rings bringing them in – are exploiting U.S. policy, which allows youngsters from Central American countries other than Mexico to be released to an adult living in the USA while awaiting their court hearing. Mexican youth are returned to an agency in that country.

Meanwhile, they continue to arrive, filling up facilities faster than officials can open them. In South Texas, where the bulk of the surge is coming through, more than 1,600 youths have filled up 13 shelters, said Kimi Jackson, of the South Texas Pro Bono Asylum Representation Project, one of the few agencies that has met with the detained children. Federal officials have also opened temporary facilities at Lackland Air Force Base in San Antonio, in Ventura, Calif., and in Fort Sill, Okla., to deal with the overflow.

The children at the South Texas facilities, overseen by ORR, live in dormitory-style bunkers, receive school instruction and legal reviews, and get to play outside, Jackson said. More worrisome are those still stuck in Border Patrol holding facilities, which are not set up to house children, she said. "The shelters are all full right now," Jackson said. "There's definitely crowding happening."

Overwhelmingly, the children cite growing gang violence in their home countries as a main motivator for making the treacherous trek to the USA, she said. The children are being reunited with their U.S. caregivers after an average stay of around 33 days at the shelters – less than half the time it was three years ago, she said.

Still, some aren't released fast enough. Linda Brandmiller, a San Antonio immigration attorney who represents unaccompanied minors, said she routinely has to battle with the shelters and ORR to release undocumented children who have proven they're fleeing hardship and have a parent in the USA waiting to take them home.

In March, Brandmiller learned of an 11-year-old Honduran girl who came to the USA through Mexico to try to reunite with her father, who was living in Alabama. It took her 2½ months to have the girl released to her father, she said.

"This is insanely expensive," she said. "Everything is costing we, the taxpayer, an unnecessary amount of money when these children have places to go."

But that policy of allowing the children to reunite with adults in the USA could be fueling the influx, said Cabrera, the border agent. The unaccompanied children often arrive with a slip of paper in their pocket with the information from their home country and the name and number of their contact in the USA. Once across the border, they're instructed to turn themselves in and play the system, he said.

"It's a loophole they've found in the system," Cabrera said. "And, frankly, they're exploiting it well."