Mexican forensic teams train at Body Farm in the United States

On a cool autumn morning here in west Tennessee, Raul Robles crouched next to an open grave, looking at the bones his team had just discovered.

He was unusually relaxed, shaking his head to salsa music playing from his cell phone as he helped measure and map the assembly of dirt-stained ribs and vertebrae.

Robles, 41, is accustomed to much more annoying conditions. Back in the Mexican state of Sinaloa, where he has excavated at least 500 hidden graves during his 15 years as a crime scene investigator, he occasionally digs under the surveillance of a drug cartel.

“The watchers come on their motorcycles without plates, with their lights off, and say,‘ You have two more hours to finish, or else, ’” he said.

When that happens, he has little choice but to take the contents of the grave onto canvas, throw it in his truck and finish his work back at the lab.

More than 93,000 people across Mexico are officially classified as missing – an astonishing total that points to a crisis of not only violence but also forensics.

Unidentified bodies are buried in a mass grave in Tijuana in 2018.

(Gary Coronado / Los Angeles Times)

In recent years there has been a growing recognition that many of the missing may be in government custody – their bodies scattered among the tens of thousands of corpses that have passed through mortuaries without being identified and later buried in mass graves. Mexican authorities have promised to give names to the human remains in their care.

That’s why Robles and 23 other Mexican crime scene researchers, forensic archaeologists and mortuaries spent five days last month at the University of Tennessee’s Forensic Anthropology Center, a world-renowned research center better known as the Body Farm.

For more than four decades, researchers at the farm have been burning donated bodies, submerging them in water, smashing their bones, wrapping them in carpets and leaving them in car trunks – all to learn more about how corpses decay in different conditions. .

Usually when they host visitors to the farm – a sloping 3-acre section of forest strewn with about 100 bodies in various states of decay – the researchers offer cautious words.

Take a deep breath, director Dawnie Wolfe Steadman tells them. And if you feel like you could faint, sit on the ground.

The Mexican visitors, who lack training but no experience, did not demand such warnings.


In 1977, forensic anthropologist William Bass was called to a cemetery in Franklin, Tenn., Where police discovered what they assumed was a recent murder victim.

Bass came to the same conclusion, estimating that based on the state of the body, the man had been dead for less than a year. He has been away for over a century.

The body turned out to be that of a Confederate soldier shot down at the Battle of Nashville in 1864. Digging for anything of value, grave robbers removed the corpse from a cast-iron coffin that prevented its decay.

For Bass, it was a transformative moment. Science, he understood, understood very little about how bodies rot.

Soon the University of Tennessee, where he worked, gave him a former dump behind the medical school to experiment on donated corpses. After community protests erupted – “this makes us sick” read one picketer – the university barricaded the area with a razor blade.

For years, Bass and his explorers operated in relative obscurity. Then in 1994 crime writer Patricia Cornwell released “The Body Farm”, a thriller loosely inspired by the installation, earning it both fame and a new nickname.

Today more than 5,000 people have registered to donate their bodies when they die. Investigators at the farm regularly act as expert witnesses in murder trials and conduct training for the FBI.

When the U.S. government asked a few years ago if it could send Mexican teams to the farm to learn about forensic excavation, the researchers soon realized they would have to adapt their typical course.

Investigators at a murder scene in Acapulco.

Investigators into a crime scene at a homicide in Acapulco, Guerrero, in 2019.

(Gary Coronado / Los Angeles Times)

Simply put, Mexican investigators work under some of the coldest and most difficult conditions in the world.

“In one grave you may find three heads and five limbs,” said Sandra Macías Gutiérrez, a mortuary from the state of Colima, during a lunch of pizza and soda during a class break one day. “The drug addicts like to dismember the bodies they have already killed, to make identification difficult.”

Many parts of her country have not been at peace since 2006, when then-President Felipe Calderón declared war on drug cartels, and killings and disappearances soared. The perpetrators – sometimes the narcotics, sometimes corrupt police – began to initiate increasingly barbaric forms of murder.

Many Mexicans closely associate the drug war with the United States, not only because of the vast U.S. appetite for illegal drugs and the large number of guns spilling south across the border, but also because the dramatic increase in violence coincided with a controversial and costly cross. -boundary security partnership called Mérida Initiative.

By order of Mexican President Andrés Manuel López Obrador, who says military access to the drug trade has transformed Mexico into a “cemetery,” a new bilateral agreement is being negotiated.

U.S. officials say they will be less focused on strengthening the Mexican military and adopting a “holistic” approach to public safety – targeting guns, funding drug treatment and supporting more forensic training programs like the one that brought the Mexicans to Tennessee.


Tensions that have strained the U.S.-Mexico relationship in recent years at the highest levels – including López Obrador’s claim that the U.S. fabricated a drug case against a former Mexican defense minister – were non-existent on the farm.

The students and their teachers tied up over their love for bones, at one point crowding around a set of ribs whose owner was suffering from a rare disease that caused parts of them to fuse.

Column One

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And they took pity on the hit TV show “CSI: Crime Scene Investigation,” which they agreed had generated inaccurate expectations about the speed of forensic investigations.

The students spent the first two days in class, taking their seats each morning in a firm ballroom at the Hilton in downtown Knoxville for several hours of lectures.

They covered the science of decay and forensic entomology, learning how to approximate the time of death based on which insects are present. With the help of Spanish interpreters, they listened intently as the teachers explained the best ways to recover evidence when a body is burned.

By the third day, they were ready to descend into the dirt. They climbed into vans and drove across town to the Body Farm.

Two people are sorting bones on a blue canvas.

Raul Robles, rightly, was one of two dozen Mexican crime scene investigators to attend a course at the University of Tennessee.

(Kate Linthicum / Los Angeles Times)

After putting on puffy white hazmat suits and blue boots, they walked the grounds. Some of the bodies they passed were mummified, with leather-like skin attached to their ribs. Others were still covered in blackened flesh. Most of their hands and feet were covered with a red plastic net to protect them from the hungry raccoons that sting here at night.

The cool, humid air meant that the smell of rot was much less intense than it would have been during the stifling summer months.

The Mexicans burst into four teams, each of which would spend the next few days digging up a mock grave.

For a typical course, researchers bury a single, intact body. But this time, to reproduce situations common in Mexico, they prepared more complex tombs, dismantling several skeletons and burying them along with various pieces of evidence.

At one grave, right next to wooden hangers, which researchers sometimes use to simulate hangers, several students quickly established a rectangular grid with stakes and rope. Then they began to deliberately remove the ground, then revealing a necklace, then a pistol and finally what appeared to be a femur.

Several stretched out on their bellies as they swept away dirt with their fingers and tiny brushes. Each time they exposed a new layer – the deepest was about 4 feet – they stopped to map and photograph it.

Researcher and student at the Body Farm

Joanne Devlin of the Body Farm sifts through dirt with Isaac Aquino Toledo, a forensic archaeologist from the Mexican state of Hidalgo.

(Kate Linthicum / Los Angeles Times)

“We want to preserve the spatial relationship of different evidence with the body,” said Joanne Devlin, associate director of the estate, who explained that preserving the specific timeline from when things were buried would be crucial to building a case later.

The Mexicans shared their own tips.

Isaac Aquino Toledo, 43, used small wooden stakes to hold the clue in place while he worked, an unusual trick that Devlin thought was great.

“Sometimes I find the footprint of a shoe and then I find that same shoe on the victim,” said Aquino, a forensic anthropologist from Hidalgo State. “It’s usually because the killers made the victim dig their own grave.”

Then, as he dug, he sighed, “I wish there would be a better way to get rid of this dirt.”

“We need a forensic dust breaker,” Devlin said. “Invent one! You can retire! “

Along with teaching best practices, the researchers showed a number of shortcuts.

“If you don’t have time or it’s dangerous, you can use this method,” Mary Davis explained to a group of students, showing them that instead of measuring each bone in a grave they could approximate by drawing them on a grid.

At another grave, Carolina Montes, a forensic investigator from the city of Tepic in western Mexico, sifted through dirt with a sieve.

She picked up a small white object that looked like a pebble.

“Is it cartilage?” asked a friend.

“I think it’s a tooth,” Montes said, depositing it in a bag of evidence.

Montes, 26, said most forensic training programs in Mexico did not teach much about excavation and that people mostly learned on the job. She found that digging the imitation grave at the Body Farm was much easier than working at home.

“The grave is not very deep and the dirt is easily pierced,” she said. “We’re used to graves with 10 people in them.”


When her students finished their work, one of the teachers, Lee Meadows Jantz, took the bones they had recovered and placed them on a blue canvas. They would be cleaned, boxed and stored for future study along with about 1,600 other skeletons.

Then she asked her team, “Have you ever buried a body?”

Several people burst out laughing – until they realized she was serious.

It is a ritual performed at the end of most Body Farm workouts. Meadows Jantz had a partially rotten corpse waiting, wrapped in canvas, ready to be placed in an imitation grave.

The Mexicans buried it under a desert honeysuckle along with some evidence. “Throw in another shoe!” one cried.

In the spring the honeysuckle bloomed with white flowers. By the end of summer, it would turn deep red. After several seasons, the body would become just bones – clues for other students to figure out.

That afternoon at a graduation ceremony at the hotel, the principal thanked the students, telling them, “I feel like we learned the same from you.”

Everyone was given a bag full of trolls, brushes and other tools of the trade – things that are missing at home.

Often, Mexican forensic investigators have to buy supplies themselves because their departments are so underfunded. Sometimes tools are purchased from local collectives of families looking for their loved ones.

The collectives who alert authorities to the location of possible graves often guard during excavation, praying loudly for their sons or daughters to be found even when they fear such a result. It is not uncommon for researchers to work to the sound of crying mothers.

“It’s very painful,” Montes said. “But I’m doing this work to help people get back to their homes.”

How to deal with those emotions is not something taught at the Body Farm.

Cecilia Sanchez in The Times ’Mexico City office contributed to this report.

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