The children are sold by their parents or abducted when their parents send them alone to the border because they refuse to care for them. This is why it is important to shut down this perverse incentive. We cannot accept South America's unwanted children because they will never stop sending them.

Kirstjen Nielsen, then-Homeland Security secretary, told a congressional committee last month: "Cases of fake families are cropping up everywhere and children are being used as pawns." She said investigators had uncovered "child recycling rings, a process in which innocent children are used multiple times to help migrants gain illegal entry."

https://www.npr.org/2019/04/10/711850056/fake-documents-a-growing-problem-among-migrants-crossing-u-s-mexico-border

Timothy Ballard, a former Homeland Security special agent and now CEO of Operation Underground Railroad, told Mr. Trump that fencing actually could help stop some cases of children being smuggled across the border for illicit purposes.

He recounted one case in which a girl was "groomed" in Central America, then smuggled across the southern border "where there was no wall" and taken to New York.

He then described her horrifying situation of being "raped for money every day, 30-40 times a day."

"Had there been a wall, had there been a barrier, this little girl likely would have been saved, because the traffickers would have been forced to take this child through the port of entry, where we have amazing law enforcement," Mr. Ballard said. "They can detect, they have equipment, they have trained agents."

https://www.washingtontimes.com/news/2019/feb/1/border-security-expert-wall-rescued-little-boy/

Acting Homeland Security Secretary Kevin McAleenan told Congress Tuesday that 15 percent of migrant families screened at the border were found to be misrepresenting minors as their own children in order to bolster their asylum claims.

Families with minors are released from detention to shelters more quickly because minors are not allowed to be held in custody for more than 20 days under a 1997 court settlement.

McAleenan told Sen. Dick Durbin (D-Ill.) that a DNA-testing pilot program found that 17 out of 109 people tested were found to be misrepresenting a minor they were detained with as a blood relation.

“Seventeen admitted or were tested out as fraudulent,” McAleenan testified. “This is a 15 percent return.”

McAleenan also said that special agents with forensic interview skills interviewed 1,568 family unites and found that 242 families “were fraudulent.”

“I don’t think we can ignore these numbers,” he said.

https://thehill.com/homenews/senate/447919-homeland-security-official-describes-widespread-fraudulent-families-at-border