Attorneys at the hearings said the immigrants had brought two dozen boys and girls with them to the US, and the judge replied that he didn't know what would happen to their children.
Footage of the crash showed four bodies on the ground, the charred Chevrolet and several Border Patrol vehicles at the scene.
White House Chief of Staff John Kelly told NPR last month that family separation "could be a tough deterrent" for others considering immigrating illegally. A fifth person later died at the hospital.
It quoted Dimmit County Sheriff Marion Boyd as saying the driver was traveling at speeds of 100 miles (160 kilometres) per hour while trying to flee from deputies.
Brane said that after an attorney started to ask questions, agents found the girl's aunt and reunited the two.
"Our deepest sympathies go out to the families of those who died in the crash", The Border Patrol said in the statement.
Some injured were taken by helicopter to San Antonio, about 90 miles (144.83 kilometers) northeast.
Nielsen said at a National Sheriffs' Association in New Orleans, "We will not apologize for the job we do, for the job law enforcement does and for the job the American people expect us to do".
The person who allegedly recorded the audio, handed it over to United States civil rights lawyer Jennifer Harbury, who has worked in the Rio Grande Valley near the Mexican border for 40 years.
Trump says Canadians are smuggling shoes out of the US
Listen to "Follow-Up" Podcast: Where Will Trump's Anti-Canada Spasm Leave Us? We want to be the smart country, ' he said. She confirmed that the United States is still insisting a new NAFTA deal have a five-year expiry clause.
The van was carrying 14 people. "This is, I think, a ideal example of why our borders need to be secure".
"It's just extremely busy, we need the assets down here, we have a problem", Boyd said. There needs to be sensors'.
As we've explained before, parents are sent to federal court under the custody of the U.S. Marshals Service and then placed in a detention center, according to Homeland Security.
The incident comes amid heightened tensions over the treatment of immigrants at the southern border.
As a result of enforcing that policy, families who cross illegally have been separated from their children because those accompanying the children are put into the criminal justice system.
That outlook is shared by Attorney General Jeff Sessions and the president.
Conway rejected the idea that Trump is using the kids as leverage to force Democrats to negotiate on immigration and his long-promised border wall, even after Trump tweeted Saturday: "Democrats can fix their forced family breakup at the Border by working with Republicans on new legislation, for a change!"
"We did see the children who were held inside here", he told CNN's Ana Cabrera in an interview.