The cardboard box was light, barely big enough to hold a baby, much less an athletic 26-year-old. Yet, it held Diego Fernando Aguirre Pantaleón, or at least his remains, excavated from a common grave in a desert in northern Mexico.
His family does not know how he ended up in the grave in Coahuila state. The authorities said he was abducted in 2011 on graduation day with six other classmates, all promising recruits for a new specialized police force trained to combat organized crime in Coahuila. Armed men had broken into the bar where the young police officers were celebrating and taken them away.
“We were dead in life, all of us,” Mr. Aguirre Pantaleón’s father, Miguel Ángel Aguirre, 66, said of his family. After his son disappeared, he would sleep on the living room sofa, waiting to hear his son’s footsteps.
It took 12 years — until February 2023 — for his son’s remains to return home in a box. His parents refused to look inside. Scientists told them his body had been burned.
It was a tragic yet uncommon resolution in a country where more than 120,000 people have vanished since the 1950s, according to government data, leaving relatives desperate for clues about their fate. Until recently, hundreds of families in Coahuila had faced the same uncertainty. But in a unique partnership, search volunteers, scientists and state officials set out to change that.
From that alliance emerged a specialized research institute — the Regional Center for Human Identification — the first of its kind in the country. It has an almost impossible task: Find the remains of the missing and send them back home.
“Dignity and human rights do not end with death,” said Yezka Garza, the general coordinator of the center based in Saltillo, an industrial city nestled in the Coahuila desert. “What we seek is for those bodies not to be forgotten again.”
The center, built next to Saltillo’s morgues, opened in 2020, supported by funds from the state government, Mexico’s federal search commission and the U.S. Agency for International Development. It has about 50 staff members — families of the missing had requested that several of them be recent graduates, seeing their young age as a sign that they had not been corrupted.
They work to find, unearth, classify, store and identify human remains nearly every day.
Since 2021, researchers have recovered 1,521 unclaimed, unidentified or undiscovered human remains from large-scale searches in state morgues, common graves and clandestine burial sites. Through genetic and forensic analysis, they have put names to 130 of those bodies, most of which, 115, were returned to families.
Many of the dead were most likely the victims of the severe violence Coahuila state endured at the hands of the Los Zetas cartel and the security forces that colluded with them, with homicides peaking in 2012. Although the cartel’s hold on Coahuila has since weakened and the state is now one of Mexico’s most peaceful, more than 3,600 people remain missing there.
The memories of shootings, disappearances and bodies hanging from bridges remain fresh for residents to this day.
“Many of my friends from high school went astray and got into organized crime,” said Alan Herrera, 27, a lawyer and searcher with the center. “They lasted a month and they killed them — 12-, 13-year-old kids.”
Mr. Herrera’s soothing voice is helpful in his line of work: making first contact with people searching for loved ones. In November, he visited the home of Jorge Bretado, 65, in Torreón, another industrial city west of Saltillo. The men sat in a cramped living room, and an interview unfolded.
Whom was he looking for? His son and his ex-wife.
What happened? Municipal police officers took them away in 2010; he never saw them again.
Did he file a police report? “No,” Mr. Bretado replied nervously. Back then, the cartel, not the law, ruled. “And they told us that they would kill the whole family if we made the report,” he said.
“I wholeheartedly hope your relatives are not with us,” Mr. Herrera said after the interview.
He then put on blue gloves and pricked Mr. Bretado’s finger to collect his blood, which researchers would use to match with DNA in their ever-growing database. If his son’s body was in one of the center’s refrigerated cabinets, Mr. Bretado would hear from him.
It’s not always easy to identify victims’ remains in Coahuila — the Zetas made sure of that. The cartel’s goal, said Mónica Suárez, the center’s lead forensic geneticist, was to make sure “there was absolutely nothing left of the person.”
If there are remains, they are often bone fragments, darkened by flames or eaten by acid. Anthropologists spend months trying to arrange them like a jigsaw puzzle. For a geneticist, those fragments, too small or degraded to have intact DNA, are not useful.
Mr. Aguirre Pantaleón’s family is among hundreds in Coahuila to get some form of closure.
On a recent afternoon, Mr. Aguirre and his wife, Blanca Estela Pantaleón, 61, visited their son’s crypt in a church in Saltillo. “I do think it was a miracle that we found him,” she said, placing a hand over the cold stone engraved with her son’s name. “Here in Mexico, they hardly find anybody.”
When Silvia Yaber heard that the remains of Mr. Aguirre Pantaleón had been found in a common grave, she wondered if her nephew, Víctor Hugo Espinoza Yaber, another police graduate abducted the same night, could also be there. She asked scientists to exhume the remains and sample the DNA of seven relatives, including Mr. Espinoza Yaber’s mother, her sister, who had died of kidney failure.
“I never stopped looking for him,” said Ms. Yaber, 66. She even went to cartel hide-outs and scoured the hills for any sign of her nephew. In August, she got news of a genetic match. The remains of her nephew had been dug up from the same grave.
On a recent day, Ms. Yaber, carrying two bouquets of flowers, went to a cemetery in Saltillo. She put the flowers on her family’s gravesite. Cement had been used to seal it again — this time with Mr. Espinoza Yaber’s remains inside.
“Your son is here now,” she remembers saying to her late sister when she had his remains added to the burial site.
Afterward, she had asked prosecutors to close the case. “It’s not justice,” she said, sitting on the grave and lighting a cigarette. “But I found him, I buried him — and that’s it for me.”
Elsewhere in Coahuila, the search for the missing continues.
Patrocinio, a vast expanse of desert about an hour east of Torreón, has become the focal point for the latest efforts, led by volunteers and scientists. Among the sand dunes, bushes and mesquite shrubs, Los Zetas members had burned victims and dug hundreds, if not thousands, of graves, searchers and families believe.
For two continuous weeks in November, a large group of archaeologists, prosecutors and relatives of the missing came to Patrocinio to unearth as many remains as they could find.
Here, death smells like diesel. A whiff of it signals you’ve come across a clandestine grave, said Ada Flores Netro, an archaeologist with the identification center who was overseeing her colleagues’ work in a freshly dug hole, where they would later unearth rusty handcuffs and bone fragments.
Most unmarked burial sites here are typically found near large shrubs, Ms. Flores Netro said: Cartel members apparently sought shade as they burned and buried their victims.
But volunteer searchers with years of experience and training — not scientists with sophisticated equipment like drones and thermal cameras — had discovered most of the recently found clandestine graves, said Rocío Hernández Romero, 45, a member of the Grupo Vida search collective who was looking for her brother Felipe.
Ms. Hernández Romero had found at least five burial sites in previous days. Her technique is more “rudimentary,” she explained, kneeling near a thorny brush and dragging a spatula along the ground to detect coloration changes or other disturbances.
“The dirt itself,” she said, “sometimes it speaks to you.”
Sheltering from the sun under a tent, a geophysicist, Isabel García, said the constant dialogue with searchers like Ms. Hernández Romero had taught her how to look for better clues about burial sites.
“We couldn’t do anything without them,” said Ms. García, 28.
Then she flew a huge drone equipped with cameras to map the graves uncovered that day.
A few feet away was an area dotted with holes in the ground where archaeologists and volunteer searchers last year unearthed the remains of Sandra Yadira Puente Barraza, 19. She and a friend went missing in 2008 after police officers stopped the taxi in which they had been traveling to go shopping.
When DNA tests matched Ms. Puente Barraza’s remains, her mother, another searcher, left a wooden cross with pink plastic roses at the spot where she was found.
“That was a rough day,” said Silvia Ortiz, leader of the search collective, while sifting buckets of dirt through a mesh to pick out bones and teeth. “It feels good in the sense that you found her. But it hurts so much.”
