A superseding indictment that was returned Wednesday afternoon adds another defendant and more charges in the case against James Matthew Bradley Jr., 60, who is accused in a smuggling operation that resulted in the deaths of 10 people in July, the Department of Justice said.

San Antonio police responded to a Walmart at 8538 Interstate 35 shortly after midnight on July 23 after an officer found a tractor-trailer behind the store with several people standing and lying in the rear of the trailer and Bradley in the cab of the truck.

The DOJ said officers discovered 39 people in the trailer at the scene, although court documents estimated the trailer contained between 70 and 180-200 people during its transport.

Authorities said a .38-caliber pistol was found inside the cab of the truck.

Bradley was arrested and has remained in federal custody.

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The superseding indictment returned Wednesday alleges that Pedro Silva Segura, 47, a Laredo man in the country illegally , participated in the conspiracy by transporting immigrants and attempting to conceal, harbor and shield them from detection.

The DOJ said Segura was arrested in Laredo on an unrelated charge and is now in custody awaiting transfer to San Antonio for a yet-to-be scheduled initial appearance in federal court.

Officials said the seven-count superseding indictment charges Bradley and Segura with the following charges:

The DOJ said the superseding indictment also charges Bradley alone with:

In a court filing Wednesday, the government announced it will not be seeking the death penalty against Bradley.

He does, however, face up to life in prison upon conviction for the conspiracy and transportation-resulting-in-death charges, as well as 10 years in federal prison if convicted of the charge of felon in possession.

Segura faces life in prison or the death penalty upon conviction of the conspiracy and transportation-resulting-in-death charges.

Both men face up to 20 years in federal prison upon conviction of the charges of conspiracy and transportation resulting in serious bodily injury.