LAREDO, Texas – The rumble of thousands of 18-wheelers coming and going across the World Trade Bridge is the constant sound of the nation's largest inland port.
The first stop for many of them, as well as other big rigs coming out of Laredo, is the U.S. Border Patrol checkpoint, about 30 miles north of Laredo.
"We have thousands of vehicles crossing the border every day. So it's a gamble for smugglers," said Aristides Jimenez, deputy special agent in charge of U.S. Homeland Security Investigations, based in San Antonio.
Whether alleged smuggler Christopher Potter came through the checkpoint last September was not mentioned in his federal arrest warrant affidavit.
Potter was taken into custody at a Frio County truck stop with 39 dehydrated immigrants locked inside the cargo hold.
Investigators said Potter was told it was empty when he picked up the truck in Laredo, so he never looked inside until after reaching the truck stop.
"Every vehicle is inspected to the best of our ability to prevent that from occurring," Enrique Martinez, assistant chief patrol agent of the Laredo sector, said. Otherwise, Martinez said he couldn't talk about the pending court case.
"It is a challenge for the agents to inspect every single vehicle, but that is our goal to inspect 100 percent," Jaime Fierro, deputy patrol agent in charge at the checkpoint, said.
Fierro said they rely on the agents, canines and technology to find people, drugs and other contraband amid 12,000 to 15,000 vehicles daily.
"It's always a balancing act. It's not easy," Jimenez said.
He said they must inspect as many as possible.
"But at the same time, we can't stop commerce," Jimenez said. "We're asking our agents to do a lot without affecting international commerce. So it's always a balancing act."
Click here to view statistics on seizures, apprehensions and rescues by the Border Patrol in 2014.