Seven of the 10 migrants who died after being transported in the back of a sweltering tractor trailer were Mexican nationals, according the Consul General of Mexico in San Antonio. 

Of the 39 victims, 34 are Mexican nationals who came from all across Southern Mexico. However, these numbers can change as the investigation moves forward, and officials say that there may have been up to 100 people in the truck at one point. 

The consulate said that only one of the migrants is a woman, and the rest are men, and that two are minors. One of the minors is still hospitalized, and the other is in care of the Office of Refugee Resettlement.

Depending on their individual situations, some may be protected by U.S. laws.

"All of them have received legal advice from the consulate. There are some that prefer to hire a private attorney and do all the process on their own," said Reyna Torres Mendivil the Consul General of Mexico in San Antonio.

The consul says she is in contact with federal officials every day.

A spokesman for the U.S. Attorney's Office in San Antonio said Wednesday that 13 of the immigrants from the truck are being held in federal custody and may be potential witnesses in the criminal investigation against the truck's driver.

At this point, the consulate is working to also get in contact with families, especially for those requiring funeral arrangements.

In addition to the victims from Mexico, according to reports, three people were from Guatemala. Two survived and one died.

The 13 potential witnesses 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.''