SAN ANTONIO (AP) - U.S. authorities have detained 13 immigrants who were found inside a sweltering tractor-trailer in San Antonio as potential witnesses in the criminal investigation.
 
A spokesman for the U.S. attorney's office in San Antonio said Wednesday that the 13 people are in federal custody.
 
The tractor-trailer was found Sunday in a Walmart parking lot. Ten people inside died. The driver, James Matthew Bradley Jr., faces a human smuggling charge that carries the possibility of the death penalty.
 
The 13 potential witnesses who are in custody will be represented by attorney Michael McCrum. McCrum told The Associated Press that all of the people are expected to give depositions in August. Some may be released before any trial. He expects authorities to hold them at one of the immigrant detention facilities in the San Antonio area.
 
McCrum says he's concerned the detained passengers will "be treated as chips in a political game instead of real people."