A man who was arrested after at least nine people died in the back of a sweltering tractor-trailer found outside a Walmart store in Texas is due in court.
Federal prosecutors say James Mathew Bradley, 60, of Clearwater, Florida, will be charged on Monday.
Officials say nearly 20 other people rescued from the back of the rig in San Antonio early on Sunday are in hospital in critical condition, many with extreme dehydration and heatstroke.
Foreign officials from Mexico and Guatemala confirmed people from those countries were found in the abandoned tractor-trailer.
US Immigration and Customs Enforcement acting director Thomas Homan said the truck driver is in custody.
The local US Attorney's Office would not say whether Bradley was the alleged driver who was arrested.