Authorities in Texas have arrested and charged the man that was allegedly operating the abandoned truck where 53 migrants died in San Antonio, Texas.

U.S. attorneys charged Homero Zamorano Jr. with transportation of illegal aliens resulting in death, a crime that comes with a sentence of “up to life in prison or death.” Three others have also been arrested and charged in connection with the case.

According to a sworn affidavit filed by Homeland Security special agent Nestor Canales and obtained by Rolling Stone, upon arriving at “the scene of a human smuggling event,” Homeland Security agents found that “48 individuals were deceased and located inside or within the vicinity of the tractor trailer.” The death count has risen to 53 since the affidavit was filed.

“[Homeland Security special agents] were advised at the scene by San Antonio Police Department (SAPD) officers that they arrived at the location of the tractor trailer after receiving 911 calls from concerned citizens,” the affidavit states. “At the scene, SAPD Officers discovered multiple individuals on the ground and in nearby brush, several of whom were deceased.”

Authorities were then “led to the location of an individual that was observed hiding in the brush before running to abscond from responding citizens.” San Antonio police officers on the scene detained Zamorano, who was escorted to a nearby hospital for medical evaluation. 

Surveillance footage provided by the Laredo Sector border patrol showed that a man matching Zamorano’s appearance and wearing the same clothing was behind the wheel of the truck at an immigration checkpoint crossing.

The San Antonio Express-News reports that Zamorano, a 45-year-old with addresses in Houston and the Rio Grande Valley, has a lengthy criminal history. A law enforcement source also told the newspaper that Zamorano was “very high on meth when he was arrested nearby and had to be taken to the hospital.”

The affidavit also detailed the nationalities — but not the names — of the deceased: 22 of the victims were Mexican nationals, seven were Guatemalan, two were Honduran and 17 were of “unknown origin but suspected to be Undocumented Non-Citizens.”

Twelve adults and four children were also found alive at the scene and were hospitalized for heat exhaustion and heat stroke. San Antonio Fire Chief Charles Hood told reporters that the individuals found inside the trailer had no access to water. Temperatures in San Antonio topped 103 degrees Fahrenheit Monday.

“We’re not supposed to open up a truck and see stacks of bodies in there,” Hood said. “None of us come to work imagining that.”