A recent Fox 7 feature is exposing the work life of U.S. Border Patrol agents assigned to Texas’ Rio Grande Valley sector, a 1,254 mile stretch where they’re nabbing about 500 illegal immigrants flooding into the country each day.

Supervisory Border Patrol Agent Marlene Castro told the news site the traffic crossing the Rio Grande River from Mexico is unrelenting and impossible to contain, despite the fact that most border jumpers willingly comply with officers.

“McAllen station is actually the busiest station in the whole country for illegal entries,” Castro said. “It’s been a group, and then five minutes later another group, and then half an hour later you’ll see another one.”

Many of those making their way north are women, children and families, while others are criminals with prior deportations, Castro said.

Castro explained how many crossing the river get into America while hosting the Fox 7 reporter for a ride-along.

Many pay smugglers to get them from Central America to the banks of the Rio Grande, where they’re ferried across in rafts into the hands of border patrol agents.

“The smuggler usually brings the raft up He’ll be sitting there with a raft and people are gathering and as soon as he has enough people, he’ll bring them across, go back, wait for another group, and bring them across,” she said. “We’re not a deterrent because they’re looking for us, so we can be standing there and he’ll still send them across.”

“They get process, they get to tell their story, they’re going to get to see an immigration judge at some point, they might be seeking asylum, there’s different reasons,” she said.

Castro said officers know they don’t catch many of the folks crossing, including criminals who exploit the heavy traffic or make their way undetected at night.

“It’s easy in the sense that they can just stand there, sit there, wait till they don’t see us in the area, and come across,” she said, adding that many criminals who are arrested have been in the United States before.

“They come in, you arrest them, you deport them, they come in again, you arrest them, you deport them, and they keep coming back,” Castro said.

“They might use (a group of women and children) as a distraction. The women and children are coming across and they’ll come in through somewhere else because we’re caught up with the women and children. Or they’ll do it in the cover of darkness, whereas women and children are mostly during the day,” she said.

In September alone, police arrested two illegal immigrants in the Austin area for murder, aggravated sexual assault and kidnapping, and both had been deported more than twice, according to the news site.

Castro took Fox 7 to a temporary holding facility in McAllen, Texas that’s currently housing 740 illegal immigrants, including 214 children who crossed alone, where Castro shared the stories of several immigrants who fled violence in Honduras, or gangs in El Salvador.

One immigrant told Castro gangs have overrun his city in El Salvador, and he was separated from his wife along the journey to America and he no longer knows where she is.

“He did see that if you’re alone, whether you’re male or female, there are risks involved. And it’s more dangerous. The women getting raped and the men being assaulted,” Castro said.

Illegal border crossings are up 63 percent for the first three weeks of fiscal year 2017, continuing an increase last year over 2015, though Castro was quick to point out the figures only reflect the people picked up by officers.

“We don’t know how many have come through and I can’t even begin to give you an estimate or a more or less,” she said. “We know we don’t catch everything.”