FOX 7 rides with U.S. Border Patrol to see what struggles they face

During the month of September, authorities arrested two undocumented immigrants in the Austin area for crimes including murder, aggravated sexual assault and kidnapping. Both of them had previously been deported more than twice.

We wanted to see how it was possible for them to enter the United States illegally so many times, so we rode with the Rio Grande valley sector border patrol to find out. Border patrol agents must secure 1,254 miles in Texas every single day.

"McAllen station is actually the busiest station in the whole country for illegal entries," said Supervisor Border Patrol Agent Marlene Castro.

During fiscal year 2016, which ended September 30, border patrol agents in the Rio Grande Valley sector apprehended about 500 undocumented immigrants per day.

"It's been a group, and then five minutes later another group, and then half an hour later you'll see another one," Castro said.

Within minutes of driving down a private road along the Rio Grande River, she pull up to a woman and child who just crossed illegally into the united states. Castro believes they are stragglers from a larger group apprehended just down the road, but that's not the story she's given.

"It's one of the things you learn from talking to people. She said she came alone, she paid 100 pesos just to cross the river, everything else she did on her own, which, I doubt it," said Castro.

Nelly tells Castro that she and her one-year-old son Joshua were assaulted by gang members in Honduras and that's why they decided to make the dangerous trek to the United States to stay with her cousin's husband in Florida. Their journey was funded by Nelly's brother who she said lives in Denver.

"They get processed, 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," Castro said.

A lot of families coming from Central America are paying smugglers in Mexico to help them get across the Rio Grande River on a raft, but families said they're not coming to the U.S. to hide from border patrol. In fact, they want to get caught

It's about a five minute hike through heavy brush from the road to the riverbank. Trails, formed by the thousands of people coming through each week, make the trip easy to navigate.

"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," said Castro.

Most of the unaccompanied children and families are traveling from Honduras which has one of the highest murder rates in the world. Because they are seeking asylum, they walk right up to federal authorities and willingly pack into transport vehicles.

"We're not a deterrent because they're looking for us, so we can be standing there and he'll still send them across," Castro said.

But border patrol agents know people with criminal histories can cross just as quickly.

"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," said Castro.

It's not uncommon for agents to arrest someone they've arrested 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.

While arrests of individuals are down compared to 2014, more Central American families are crossing illegally into the United States this year. At the same time, thousands of criminals are finding a way through the southern border.

"They might use that 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 mostly during the day," said Castro.

A quick walk to the road and a one-minute drive and she locates another group. Again, they are family units. All, but one, from Honduras. This time there is also a handful of unaccompanied minors. Most say they paid about $8,500 to smugglers in order to escape gang violence in their home countries. All of them raise their hands when asked if they wanted to be apprehended.

"They said yes because security is important to them," Castro said.

After they are loaded into transport vans, they are taken to a temporary holding facility in McAllen. 740 people are currently staying in the building, 214 of them children who crossed by themselves. They have access to food, water, bathrooms, toiletries, and a safe place to sleep. It's already a better way of life than the one they left behind.

"He said the gangs in El Salvador are running, not just the neighborhood, but the city. And the police department, he found out that even the police officers are asking for asylum. And he said, 'if the police officers are scared, what chance do we have,'" Castro said while talking to Carlos Quintero Arevalo, an undocumented immigrant in the holding facility.

But the price Arevalo paid to get here is hard to forget.

"He said that the journey is very dangerous. There's lots of risks involved. And I asked him if there were any incidents or something he wanted to talk about. He goes, 'I was separated from my wife.' He doesn't know where she is," said Castro.

Many make the trip knowing they will be subjected to violence, hoping their sacrifices will pay off.

"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.

Agent Castro said the number of undocumented immigrants increased from 2015 to 2016. And in the first three weeks of fiscal year 2017, it jumped another 63 percent. Of course, those numbers only include the people that have been apprehended.

"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. We know we don't catch everything," said Castro

It's a problem that isn't going away.

"We all need to come together to find a solution. There is a solution somewhere, but we all have to be able to sit down and talk," Castro said.

Until they find the answer, border patrol agents will be driving up and down the 1,254 mile stretch of the Texas / Mexico border putting their lives on the line to keep criminals out, and save the thousands who risked it all to find a better life in the United States.