In the frantic minutes after hundreds of illegal immigrants were discovered dead inside a tractor-trailer in the Texas heat, the driver attempted to flee by posing as one of the survivors, according to a Mexican immigration officer.

The American truck driver, along with another American and two other men, remained in detention as the investigation into the tragedy that resulted in the deaths of 53 people at the U.S.–Mexico border continued. According to federal prosecutors, two of the accused, including the driver, face charges that could result in life in prison or the death penalty.

Since the discovery of 46 bodies on Monday at a crime scene near vehicle salvage yards on the outskirts of San Antonio, the death toll has steadily risen, with two more victims dying Wednesday.

Francisco Garduo, director of Mexico's National Immigration Institute, stated that 27 Mexicans, 14 Hondurans, seven Guatemalans, and two Salvadorans were among the 67 persons who perished in the accident.

The Bexar County Medical Examiner's Office reported that 37 of the fatalities had plausible identifications as of Wednesday, pending confirmation with authorities in other nations. It was stated that forty of the victims were male.

Some of the deceased were discovered without identifying documents; in one case, a stolen ID was found. Remote areas in Mexico and Central America, where some illegal immigrants originated, have no phone coverage to contact family members, and governments must share and compare fingerprint data.

The family of Javier Flores López awaited word as to whether he was aboard the truck. After visiting his wife and three young children in southern Mexico, he returned to Ohio, where his father and brother lived and worked as a construction workers. His family said he is now among the missing and that his cousin José Luis Vásquez Guzmán is hospitalized in San Antonio.

The tragedy occurred when a large number of illegal immigrants were entering the United States. In May, illegal immigrants were stopped approximately 240,000 times, a 33 percent increase from the previous year.

Although it is unclear when or where the illegal immigrants boarded the truck heading for San Antonio, Homeland Security officials suspect it occurred on U.S. soil, near or in Laredo, Texas, according to Texas Representative Henry Cuellar (D).

According to Cuellar and Mexican officials, the vehicle passed a Border Patrol checkpoint northeast of Laredo on Interstate 35. It was registered in Alamo, Texas, but featured counterfeit license plates and emblems, according to Garduo.

Officials in Mexico also released a surveillance image of the driver smiling at the checkpoint during the almost two-hour journey to San Antonio.

On Wednesday, Greg Abbott, the Republican governor of Texas, announced that state troopers would set up additional truck roadblocks on highways but did not specify how many.

Authorities investigated if the truck had mechanical issues when it was abandoned next to a train track. Garduo stated that the driver was detained after attempting to disguise himself as one of the illegal immigrants.

The driver was identified as Homero Zamorano Jr., 45, who was accused of smuggling resulting in death by federal authorities. According to the U.S. Attorney's Office in San Antonio, Zamorano lives in a Houston suburb and is originally from the Texas border city of Brownsville.

Along with Christian Martinez, 28, accused of conspiracy and reportedly talking with Zamorano about transporting illegal immigrants, he faces the most serious allegations.

Martinez was apprehended in East Texas and will be taken to San Antonio. Thursday was expected to be Zamorano's first court appearance. It was initially unknown whether one of the suspects had an attorney.

Two further non-citizens were arrested on allegations of illegal possession of firearms. According to the prosecution, the males were located at the San Antonio address where the truck was registered.

According to Rubén Minutti, Mexico's consul general in San Antonio, several more than a dozen victims evacuated to hospitals were discovered to have suffered brain damage and internal bleeding.

Craig Larrabee, acting special agent in charge of Homeland Security Investigations in San Antonio, stated that illegal immigrants typically pay between $8,000 and $10,000 to be transported across the border, loaded onto a tractor-trailer, and driven to San Antonio, where they transfer to smaller vehicles en route to their final destinations in the United States.

He stated that the death toll from Monday's disaster in San Antonio was the highest ever from attempted smuggling in the United States. Ten people died in 2017 after being trapped inside a truck parked at a Walmart in San Antonio. The bodies of 19 illegal immigrants were discovered in a hot truck southeast of the city in 2003.

Monday's temperatures in San Antonio surpassed 100 degrees Fahrenheit (38 degrees Celsius), and hospitalized patients were hot to the touch and dehydrated, according to authorities.

Jennifer Vanos, an assistant professor at Arizona State University who has studied child deaths in hot automobiles, said that it would not have taken long for the temperature inside the truck to become lethal.

She claimed that because of the excessive humidity, lack of air movement, and many individuals within the tractor-trailer, their sweat could not evaporate to cool their bodies, and they would have rapidly become dehydrated.

Among the obstacles in identifying the victims were counterfeit or stolen documents.

The secretary of foreign affairs of Mexico identified two hospitalized individuals in San Antonio on Tuesday. It turned out, however, that one of the identification cards he uploaded on Twitter had been stolen in the southern state of Chiapas the previous year.

When she was 23 years old, Haney Antonio Guzman was safe in a mountain village almost 1,300 miles (2,092 kilometers) from San Antonio when she began getting texts from concerned family and friends.

Antonio Guzman stated, "My name is on the ID, but I am not the person who was in the trailer and is reportedly hospitalized." My anxious relatives were inquiring about my whereabouts.