SAN CRISTÓBAL DE LAS CASAS, Mexico – Several months ago, Mercedes de María Santiago Gomez set one too many places at the table for the last time.

Her youngest child, Lidio Javier de la Cruz Santiago, was 18 when he left the cobblestone streets here in the highlands of Chiapas in 2005. He headed north for work, she said, in the way everyone in Mexico means: north to the United States. The family didn’t need the money. Her husband, Javier Magin, worked in construction and as a mariachi musician, and Mercedes had a small cooking and cleaning business. But Lidio wanted to prove himself.

Lidio planned to make the dangerous journey with other young men from San Cristóbal, and Javier tried to talk him out of it, urging him to stay and finish his studies. His boy – nicknamed “Zorrillo,” local slang for skunk, because he shunned showers and always brought home animals – was headstrong, Javier said, smiling through tears. Still, he went with Lidio to meet the who would guide them across the border.

“He said all the right things,” Javier said of the smuggler. So he gave Lidio the $5,000 fee and put him on a bus on July 13, a Wednesday, his parents recalled. In a few days Lidio would reach Sonora in northern Mexico, just south of Arizona, where he would cross the border.

But Lidio soon stopped answering his phone. His companions from Chiapas stopped answering, too, after they told Javier that the guide had ditched his son in the desert by a state highway, where he said U.S. Border Patrol would pick him up.

Lidio’s parents posted photos of their son everywhere: a serious young man, with spiked black hair and a round face. They filed missing person reports with local and state officials and with Mexican consulates in California and Arizona. They heard nothing.

Then, last September, they learned what they desperately needed to know and not know for more than a decade after Lidio got on that bus: Investigators had found a DNA match to a John Doe in a collection of migrant remains in Arizona.

As the had promised, U.S. Border Patrol had found Lidio. But they found him in December 2005. By then, months after authorities believe he died, he was just bones.

Don Javier and Doña Mercedes are still waiting for him to come home.

Deaths in the desert

Apprehensions at the border – a proxy for the number of illegal crossings – have fallen sharply since 2000 and most dramatically since the fallout from the financial crisis and economic downturn around 2008, according to the Pew Research Center. Since the recession, the number of unauthorized Mexican immigrants has declined by roughly 1 million, and net migration from Mexico has in fact reversed.

But many who do cross are dying in the desert. Migrant deaths on American soil increased by more than 50 percent in the seven years after U.S. Border Patrol began tracking them in 1998. The year Lidio died, 2005, was the deadliest ever recorded for migrants, with 492 total deaths. Despite the dramatic drop in illegal crossings since 2006, migrant fatalities haven’t fallen with them: For six of the last 10 years, total fatalities have neared or topped 400.

That’s likely because while many Central Americans immediately turn themselves in to U.S. immigration authorities knowing that they can make a claim for asylum, Mexicans know they will be rapidly removed and take far greater risks to evade authorities.

Experts tie the rise in migrant deaths – more than 7,000 have died on U.S. soil since Border Patrol started counting, or one a day for nearly 20 years – to the U.S. crackdown on illegal immigration beginning in the 1990s.

By putting personnel, surveillance technology, and infrastructure on the border, “illegal traffic will be deterred, or forced over more hostile terrain, less suited for crossing and more suited for enforcement,” Border Patrol concluded in its first national strategy, in 1994.

Hess’s office in Pima County, Arizona, holds the country’s largest set of unidentified border-crosser reports. He said migrant deaths have risen with shifts in border enforcement intended to deter border-crossers.

“But rather than decrease the number of people crossing, they just moved them, to where they now cross in more remote areas,” Hess told me in late December.

A recent from the Congressional Research Service also notes the likely “diminishing returns” and potentially deadly downside to perpetually growing the U.S. immigration enforcement regime – especially the border wall .

Each added mile of fencing “would be in ever more remote locations, and therefore more expensive to install and maintain and likely to deter fewer unauthorized migrants,” the report found, adding that the “concentration of enforcement resources on the border may increase border area violence and migrant deaths.”

Last December, Border Patrol agent David Jimarez took me around the Tucson sector, which encompasses about 3,800 square miles. There, a border wall ran west into distant mountains; to the east, it stopped abruptly, ending in a squat vehicle barrier. That’s because there’s nothing here but desert brush and jagged peaks, save a few mantis-like rescue beacons that flash periodically.

For Jimarez, a Mexican-American born in the United States, the tension between being both first responder and first line of defense is personal. He said he doesn’t want to know what happens to the people they find, alive or dead. It’s too hard.

“Those people would’ve died if I didn’t arrest them,” he said. “We’re rescuing them from themselves.”

General Kelly is doing a great job at the border. Numbers are way down. Many are not even trying to come in anymore.

– Donald J. Trump (@realDonaldTrump) March 27, 2017

“Fewer people are putting themselves and their families at risk of exploitation, assault, and injury by human traffickers and the physical dangers of the treacherous journey north,” Kelly said.

Yet, according to Border Patrol’s own data, some 121 migrants died between October and March – almost 25 percent more than the same time last year.

Jimarez, standing in the shadow of a 20-foot-high section of border fence, pointed out dusty handprints on the bars, an indication that someone had recently climbed over.

“You could build a 100-foot wall,” he said, “and they’ll build a 101-foot ladder.”

The things they carried

On Dec. 8, 2005, Border Patrol agents found a skull and scattered bones in Pinal County, Arizona. Three months later and four miles away, in Pima County, in the desolate Sasabe corridor that Jimarez patrols, agents found another set of bones. Authorities had no reason to believe they came from the same person.

In late December, I drove out to where the second set was found, 13 miles down a washed-out road from the tiny town of Red Rock, between Tucson and Phoenix, about 100 miles north of the U.S.-Mexico border. Beyond the silhouettes of 10-foot-tall Saguaro cactuses, the lights of Phoenix emerged, deceptively close. Before he died, Lidio would have been able to see his likely destination.

When agents find remains, all of the things people carry – credit cards, scraps of paper with scribbled numbers, photos of children, rosary beads, watches, smartphones, wedding rings, reading glasses, a belt buckle – become clues in trying to identify them, Hess said, gently removing some items from lockers at his office.

But even those clues are often not enough: From 1998 to today, only 57 percent of Mexican migrants who have died and been found in the Arizona desert have then been identified and repatriated, according to the Mexican consulate in Tucson.

The deceased in Hess’s collection are mostly unidentified Hispanic males between 20 and 35 years old, but the range is depressingly wide.

Some have names: Maria Dolores Moreno-Trejo died in 2002 at the age of 10 from blunt force injury to her skull. “Baby Boy Pedro” Bautista was a 26- to 28-week-old “nonviable fetus.” Leandro Bautista Alba was 58 and probably died of hypothermia, the most common cause of death in the southern Arizona desert, where temperatures can hit 125 degrees during the day and plunge at night. Others met more violent ends, such as “multiple gunshot wounds” and “asphyxia due to hanging.”

For identification purposes, even a single shard of bone can yield a wealth of information, such as sex or a specific health condition, Hess said. But if remains are scattered by animals or mostly decomposed, as Lidio’s were, identification becomes much more difficult.

After failing to identify Lidio’s remains, Hess’s office released them – still believing they were from two people – to the counties, which arranged for them to be interred in John Doe plots in public cemeteries. They would stay unidentified for almost another decade – until a last shot paid off for Javier and Mercedes long after they’d given up.

In 2012, the Argentine Forensic Anthropology Team, or , founded in 1984 to investigate Voces Mesoamericanas Acción con Pueblos Migrantes desaparecidos, or disappeared persons, during Argentina’s military dictatorship, and , an NGO in San Cristóbal, joined forces to try to build a DNA database of missing migrants. In 2014, more out of solidarity with other families of desaparecidos than hope of finding Lidio, Javier and Mercedes gave EAAF investigators a saliva sample.

Then, in September 2015, the EAAF investigators contacted Hess’s office: They had made a blind hit to the state’s collection and had matched the DNA from the saliva sample Javier and Mercedes gave with the two sets of remains. In September 2016, the investigators felt confident enough in the match to notify the Mexican consulate in Tucson, which ultimately notified Javier and Mercedes.

Hess, who was able to close one of the 900 “unidentified” files he has open, personally appended the death certificate in December.

His entry now has a name: Lidio J. de la Cruz Santiago, found in the Sasabe corridor, “date of death” Dec. 8, 2005, cause “undetermined.”

It was news his family had desperately sought and deeply dreaded. When a missing migrant’s remains are found and identified, “it’s a new torture” for the family, said Floridalma Pérez González, who works with Voces Mesoamericanas as a counseling director.

“Now they know, but there is no closure,” she said. “They can’t move on because they can’t get him back.”

U.S. and Mexican officials, NGOs, and local funeral services involved in Lidio’s case all point to someone else responsible for the delay in bringing his remains back to San Cristóbal – and someone else to blame for his ever having left at all.

Officials in the Mexican consulate in Tucson said in late December that Lidio’s remains would soon be sent back to the family in San Cristóbal. They were just waiting on the green light from Mexico City to pay for exhuming the remains, a more expensive process than usual, given Lidio had been buried so long and in two places.

Before his remains were dug up and sent home, I tried to see just where Lidio had spent the last decade. But no one at the time – not Hess, the Mexican consulate, the county authorities, funeral homes, or cemeteries – could tell me exactly where he was.

“We’ve never lost any, to my knowledge,” Hess said.

I got as close as I could. In the public section of the Mountain View Cemetery in Casa Grande, Arizona, in Pinal County, among the muddy teddy bears and rusted crosses, were a dozen barely discernible mounds of dirt: the John Does. A few plastic placards stuck out, but none were labeled. County officials told me Lidio was there.

Other officials from neighboring Pima County told me he was there, too, in the burnt orange columbarium in the public section of Evergreen Cemetery in Tucson that holds their John Does.

Mercedes and Javier don’t know many of these details. They can’t afford the trip to Arizona and fear trouble with U.S. immigration officials, even when visiting legally. They still don’t understand how their son is in two places, where his belongings are, and why his remains have not yet been sent home for a proper burial.

When I contacted the Mexican consulate at the end of March, officials said they had been working with the Pima County-contracted funeral home that initially had cremated and interred a portion of Lidio’s remains in Evergreen Cemetery. The home had located, exhumed, and joined the remains with the matching set buried in Mountain View Cemetery in Pinal.

Once the appended death certificate is processed, the funeral home will deliver Lidio’s cremated remains to the consulate, which will send them to San Cristóbal, the officials said.

Lidio will have a place waiting for him there, in Javier and Mercedes’s parish cemetery.

“We don’t know the truth, so we have no peace of mind,” Javier told me in December.

“Until he is here,” Mercedes said, “we will never really, truly know.”

Update, April 21, 2017: On April 19, the Mexican Consulate in Tucson told Foreign Policy that an urn containing Lidio’s remains had finally been sent back to Mexico, where his father Javier received it.

Reporting for this article was also supported by the Top image credit: Molly O’Toole (left)/Courtesy of Javier Magin and Mercedes de María Santiago Gomez (center)/Tim Bowden (right)/Foreign Policy illustration International Women’s Media Foundation as part of the Adelante Latin America Reporting Initiative. Tennessee Jane Watson contributed research.

Molly O’Toole is a senior reporter at Foreign Policy, covering immigration, refugees, and national security. She was FP’s sole 2016 presidential campaign reporter, on the trail from New Hampshire to Nevada. Previously, she covered the politics of national security for Atlantic Media’s Defense One, where she reported from Congress, the White House, the Pentagon, and the State Department. Before that, she was a news editor at the Huffington Post. Molly has also reported on national and international politics for Reuters, the Nation, The Associated Press, and Newsweek International, among others, from Washington, New York, Mexico City, and London. She received her dual master’s degree in journalism and international relations from New York University and her bachelor’s from Cornell University and in 2016 was a grant recipient of the International Women’s Media Foundation. She will always be a Californian. (@mollymotoole)