EL PASO, Texas (KVIA) -- Robert Almonte travels the country lecturing and advising law enforcement agencies on how to improve policing.
Before that, he served as a U.S. Marshal, a D.E.A. agent, and an El Paso Police officer.
Almonte was one of the founding members of a group that brought together several agencies to crack down on stash houses.
Some of his investigative techniques are still used to this day.
"In most cases, when they're renting a home, they're gonna pay the rent upfront, up to a year in rent, even a cash deposit," said Almonte.
Almonte offered to take ABC 7 around town. He showed us what authorities look for when trying to find a stash house. He says these tips can be used by anyone.
Almonte took us to a home in East El Paso, one formerly busted by a task force.
"I'm gonna show you typically what's used in these stash houses. When you see something like this," he points to empty water jugs inside a trash bin, "that tells me it's being used to give drinks to several people in the house."
Almonte says as many as 25 migrants were found by the task force inside that eastside home. He says many times, migrants are being held against their will in deplorable conditions.
The retired U.S. Marshal says some stash houses standout with high security systems, like tall gates and security cameras, together with padlocks and chains. In other cases, Almonte says human smugglers will use apartment complexes to stash migrants.
As many as 250 stash houses have been found by law enforcement agencies in El Paso this year alone.
He says one of the biggest reasons the Borderland sees so may stash houses is because resources are limited.
He believes more Customs and Border Protection officers at the ports of entry are needed to combat the problem.
"It's physically impossible to search every vehicle coming across the port of entry. We don't have enough dogs to run dogs on every car. So just knowing that, the cartels know that. That's why they continue to bring massive amounts of drugs, and smuggle people across the border."
Watch my special report "Spotting a Stash House" Thursday night, only on ABC-7 at 10.