Traci Watson

Special for USA TODAY

For the nameless man whose remains were found in the Arizona desert, death was merely the final ordeal in a life full of misery.

Analysis of the man’s skeleton showed pitting of the skull, strongly pointing to childhood malnutrition. A trauma had deformed one arm, and untreated cavities speckled his mouth.

After death, his luck turned: his skeleton fell under the care of members of the small cadre of anthropologists and other experts who apply the tools of science to undocumented immigration.

Using DNA testing, bone measurements and other techniques, these researchers work to pin names on the anonymous thousands who have perished on their way to the United States. Some of the researchers also hope to foster understanding of would-be immigrants, an ambitious goal when huge crowds cheer a presidential candidate with staunchly anti-immigration views.

“The narrative you hear on TV is not necessarily reality,” says Jared Beatrice of The College of New Jersey, who has analyzed skeletons of undocumented migrants in Arizona. “People are … desperate to escape poor living conditions. And we can see that in the remains.”

Since 2001, staff in Pima County, Ariz., alone, have studied the remains of more than 2,300 confirmed or suspected border crossers, says Bruce Anderson of the county’s Office of the Medical Examiner. A similar number of remains was recovered in Texas over the same time period, according to Border Patrol statistics. The cause of death for about half can't be determined, and most of the rest died of heat or cold.

Many migrants are found with false IDs or none at all, so scientists often rely on DNA to identify aged remains. The man with the deformed arm, for instance, was successfully identified via DNA and his remains returned to his home country. Scientists decline to reveal more details to protect his family’s privacy.

Data from the remains also yield surprising findings about those who risk their lives to reach the United States. Migrants found in Texas are distinct from those found in Arizona, says Kate Spradley of Texas State University: Those found in Texas are “more similar to Americans.”

Some of the Texas migrants had fancy dental work, such as bridges and high-quality fillings. Those studied by researchers were generally free from severe cases of bone deformities tied to childhood malnutrition.

Their remains suggest they’re “fleeing violence,” Spradley says, not “extreme poverty.” That’s in keeping with the origins of Texas migrants, who tend to come from Central America, where several countries suffer from high murder rates.

A very different picture emerges of suspected migrants found further west. When Beatrice and his colleague Angela Soler, now of New York City’s Office of Chief Medical Examiner, studied the remains of 200 people found in Pima County, they found rates of bone deformity that were “kind of unbelievable,” Beatrice says.

The researchers found the presumed migrants had suffered from childhood malnutrition and other ills at proportions seen in medieval times. “We shouldn’t be seeing this in a modern group of people,” Beatrice says. Unlike the Texas migrants, the Arizona dead whose identities are learned come mostly from Mexico.

Researchers are now working on new techniques to pinpoint the origin of anonymous bones. Preliminary analysis shows, for example, that Mexican migrants’ bones have lower levels of aluminum, found in deodorant, than the bones of a comparison sample of New Yorkers, says Baylor University’s Lori Baker. The New Yorkers also had higher bone levels of a metal used to line cans.

Even groups aiming to cut legal immigration say that campaigns to identify the dead are the right thing to do. But “the best way to avoid people dying in the desert is to deter them from ever putting themselves at risk in the first place,” says Ira Mehlman of the Federation for American Immigration Reform, via email. Instead, current policy “is actually encouraging people to risk their lives.”

Hostility to the identification efforts themselves can run high. Spradley has been told, for example, that this isn’t America’s problem and skeletons should just be sent home.

The obstacle is that “we don’t know where home is,” she says. “ These individuals have families who are actively searching for them. … If that happened to me, I would want someone doing the same thing.”