SAN ANTONIO — In the chaotic minutes after dozens of migrants were found dead inside a tractor-trailer sweltering under the Texas sun, the driver tried to slip away by pretending to be one of the survivors, a Mexican immigration official said Wednesday.

The American truck driver, along with another US citizen and two other men, remained in custody as the investigation continued into the tragedy that killed 53 people in the nation’s deadliest smuggling episode on the US-Mexico border. Federal prosecutors said two of the suspects, including the driver, face charges that carry a potential sentence of life in prison or the death penalty if convicted.

Two more people died Wednesday as the death toll slowly climbed since the discovery of 46 bodies Monday at the scene near auto salvage yards on the edge of San Antonio.

The truck had been packed with 67 people, and the dead included 27 from Mexico, 14 from Honduras, seven from Guatemala and two from El Salvador, said Francisco Garduño, chief of Mexico’s National Immigration Institute.

Officials had potential identifications on 37 of the victims as of Wednesday, pending verification with authorities in other countries, according to the Bexar County Medical Examiner’s Office. Forty of the victims were male, it said.

Identifying the dead has been challenging because some were found without identification documents and in one case a stolen ID. Remote villages where some of the migrants came from in Mexico and Central America have no phone service to reach family members and fingerprint data has to be shared and matched by the governments involved.

Javier Flores López’s family was waiting to find out whether he was on the truck. He had returned home to see his wife and three small children in southern Mexico and was going back to Ohio where his father and a brother live and he worked in construction. He is now among the missing and his cousin, José Luis Vásquez Guzmán, is hospitalized in San Antonio, the family said.

Migrant surge

The tragedy occurred at a time when huge numbers of migrants have been coming to the US, many of them taking perilous risks to cross swift rivers and canals and scorching desert landscapes. Migrants were stopped nearly 240,000 times in May, up by one-third from a year ago.

While it’s not clear when or where the migrants boarded the truck bound for San Antonio, Homeland Security investigators believe it was on US soil, near or in Laredo, Texas, US Rep. Henry Cuellar told The Associated Press.

The truck went through a Border Patrol checkpoint northeast of Laredo on Interstate 35 on Monday, Cuellar and Mexican officials confirmed. It was registered in Alamo, Texas, but had fake plates and logos, Garduño said.

Officials in Mexico also released a surveillance photo showing the driver smiling at the checkpoint during the more than two-hour trip to San Antonio.

More checkpoints

Republican Texas Gov. Greg Abbott said Wednesday that state troopers would set up additional truck checkpoints on highways, but he did not say how many. In April, Abbott gridlocked the 1,200-mile Texas border for a week by requiring every truck entering the state to undergo additional inspections as part of his ongoing fight with the Biden administration over immigration policy.

Authorities were looking into whether the truck had mechanical problems when it was left next to a railroad track. The driver was apprehended after trying to disguise himself as one of the migrants, Garduño said.

Truck driver to face charges

Federal prosecutors identified the driver as Homero Zamorano Jr., 45, who was charged with smuggling resulting in death. Zamorano lives in suburban Houston and is originally from the Texas border city of Brownsville, according to the US Attorney’s Office in San Antonio.

He faces the most serious charges along with Christian Martinez, 28, who is accused of conspiracy and allegedly communicated with Zamorano about transporting the migrants.

Martinez was arrested in East Texas and will be transported to San Antonio. Zamorano was scheduled to have his first court appearance Thursday. It was not immediately known if either suspect had an attorney.

Two other men who are not US citizens were also arrested on charges of illegal weapons possession.

Prosecutors say investigators found the men at a San Antonio address where the truck was registered.

Some of the more than a dozen people transported to hospitals were found suffering from brain damage and internal bleeding, according to Rubén Minutti, the Mexico consul general in San Antonio. (AP)