KFOX14 Investigates discovers the US government spent millions of dollars in Central American countries to try and deter immigration.
In the country's largest border city, the mission to safeguard America falls to the men and women of the U.S. Border Patrol.
We get rare access to their daily operations as they hold the line.
“U.S. Border Patrol agents go out every night along the borders of the United States to enforce the rule of law, under some of the most difficult and dangerous conditions,” said Border Patrol El Paso Sector Chief Aaron Hull.
We joined up with agents along the Rio Grande. Here, agents don't have much time to act before people can cross and blend in.
Just minutes after setting out, we spot three men trying to cross with a rope ladder.
They race back when they see us.
“It’s never ending,” said Agent Fidel Baca.
At any given moment agents can be called to jump into action; on this day, it'sa treacherous smuggling route.
They’re on the trail of a group of six teens spotted here.
“We should have no footprints because of the rain, so if we see something, it's recent,” said Baca.
In places that are too rugged for a wall, agents are the only defense.
“No camera can make an arrest,” said Hull.
Hull leads some 2,500 agents working a nearly 300-mile stretch of border.
The pace? Nonstop.
We race down the mountain for another call to find a man from Juarez and two from India.
Ivan, 20, tells me his wife is in El Paso.
He's been deported before. He keeps trying.
It’s worth risking jail time, he told us, rather than getting killed in Mexico.
But, because he's with two Indians, agents are skeptical of his story – he could be a smuggler.
As night falls, agents prepare for a rise in traffic.
“It’s like we are playing tag and we are always it,” said Baca.
Agents use a mixture of old and new technology.
“Unattended ground sensors, cameras, remote video surveillance systems, some of the old technology is still the most reliable for us,” said Hull.
Some places along the border have less coverage.
Just about 40 miles outside El Paso, a barbed wire fence and smaller fence is all that stands between Mexico and the United States.
With the challenge of securing the border comes the human face.
Elizabeth is caught carrying her daughter Jaime. They’re fleeing violence and poverty in Guatemala.
“I will risk everything for her, I would give my life for her,” she says.
She’s looking to earn a better life.
“I will clean floors, toilets, bathrooms,” said Elizabeth.
The agency says about 60 percent of apprehensions are from countries other than Mexico.
The majority of them come from El Salvador, Guatemala and Honduras.
We discovered the U.S. government spent hundreds of millions of dollars since 2014 to try to deter people from leaving those countries.
Money went towards things like education and gang intervention programs, with seemingly little effect.
“The hardest thing for us is seeing the kids when they are by themselves or they are in sad shape or they haven't eaten for a while,” said Agent Tomas Schwieger.
For agents holding the line, this is a delicate balance between safety and compassion.
“The primary mission is to law enforcement but the humanitarian is always there,” said Baca.
Every month thousands will continue to test our borders and when they do, these agents, will be there.
During our ride-along, the El Paso sector averaged 125 apprehensions a day.