The parking lot of a Walmart, where a truck trailer was found with 8 deceased immigrants.

A man charged in Texas with transporting unauthorized immigrants in a stifling truck told investigators he had no idea that they were inside until he stopped and found dozens of dead and dehydrated people in the back, court papers showed on Monday.James Matthew Bradley Jr., 60, was arrested on Sunday and could face the death penalty after authorities found eight men dead in the back of his tractor trailer truck parked outside a Walmart store in San Antonio.Scores of other immigrants, including children, suffering from dehydration and heat stroke , were also inside. Two of them later died after being hospitalized, bringing the death toll to 10.One of the immigrants aboard later described to investigators unbearable conditions inside the crowded, pitch-black interior. People took turns to gasp for air through a hole in the trailer's side, the unidentified passenger said. Some passed out, while others shouted and banged to get the driver to stop. Their pleas were fruitless until they arrived at the Walmart, the witness said."To maximize their criminal profits, these human smugglers crammed more than 100 people into a tractor trailer in the stifling Texas summer heat," said Thomas Homan, the acting director of U.S. Immigration and Customs Enforcement."Human smugglers have repeatedly demonstrated that they have absolutely no regard for human life," he said in a statement.Crossing the border from Mexico has long been a dangerous proposition, according the U.S. Customs and Border Protection. Since 1998, the total number of documented deaths stands at more than 7,000, with peaks in 2005 and 2012. Even those numbers could understate the risks, as Border Patrol said it only tallies the deaths when the agency finds the bodies, and the figures may exclude some deaths reported to local authorities.Bradley told investigators at the scene he did not know anyone was inside the truck until he parked near the store to use the bathroom and heard banging and shaking coming from the back, according to the criminal complaint.When the driver opened the back doors of the trailer, he noticed "bodies just lying on the floor like meat," according to the interview summary. Some 30 or 40 people got out and "scattered," Bradley told investigators.San Antonio police found Bradley inside the tractor in the front in the rig when they arrived, according to an account in the criminal complaint.He told investigators he was driving the trailer from Iowa to Brownsville, Texas, to deliver it to the new owner. At one point he stopped in the Texas border town of Laredo to get the vehicle washed and polished before heading to San Antonio.After parking outside the Walmart, he said he heard the banging and shaking. After opening the doors he said he "was surprised when he was run over by 'Spanish' people and knocked to the ground," according to the complaint's summary.He called his wife but did not call 911 for emergency services, according to the court documents.The complaint also included summaries of interviews with people inside the truck.The immigrants, who were not named in the complaint, all described getting on the truck at various points on the U.S. side of the border. One said 70 people were already inside when he got on, while another estimated the total at 180 to 200 people. One said they were told they would have to pay smugglers $5,500 after arriving in San Antonio.Six black sports utility vehicles were waiting outside the Walmart when the truck doors were opened, one rider said, and some of the immigrants quickly "swarmed" the SUVs. That contradicted the account of Bradley, who told investigators he did not see any vehicles waiting to pick up passengers.San Antonio Police Chief William McManus said video footage showed several other vehicles coming to pick up people who were inside the truck.Two people died later at hospitals and dozens of others were treated, officials said. Some immigrants came from Mexico, officials said. Among the dead was a 20-year-old man from Guatemala City who was not identified and at least two Guatemalans were found alive but dehydrated, the Guatemalan foreign ministry said. Outside temperatures topped 100 Fahrenheit (37.8 Celsius) on Sunday.Bradley appeared briefly in federal court in San Antonio to be charged under a law that makes it illegal to transport an immigrant while knowing the person is in the country illegally or in "reckless disregard" of that fact. If convicted on the single count, Bradley could face the death penalty or life in prison.Pyle Transportation, which owned the truck, confirmed it was sold a month ago and Bradley was hired to take it to Brownsville, according to a person answering the telephone at the company, who declined to give her name.Alfredo Villarreal, an assistant federal public defender and one of two lawyers representing Bradley, did not respond to a request for comment.Mexico's government said its consul general in San Antonio was working to identify the victims' nationalities.U.S. President Donald Trump, a Republican, has vowed to crack down on immigrants living in the country illegally.In what is considered the worst illegal immigrant smuggling case in U.S. history, 19 people died after traveling in an 18-wheeler truck through Victoria, Texas, in 2003.This month, 72 people from Latin America were found in a trailer in Laredo. In June, 44 people were found in the back of a vehicle in the same Texas city, which lies directly across the Rio Grande from Mexico.

© Thomson Reuters 2017

(Additional reporting by Barbara Goldberg and Jonathan Allen in New York, Letitia Stein in Tampa and Sofia Menchu in Guatemala City; Editing by Frank McGurty and Jeffrey Benkoe)