On a cold autumn morning in eastern Tennessee, Raul Robles squatted beside an open grave, investigating the bones his team had just unearthed.
He was extremely relaxed, shaking his head while playing salsa on his cell phone, while helping to measure and draw the combination of dirty ribs and vertebrae.
Robles, 41, has become accustomed to more tragic conditions. Back in Sinaloa, Mexico, during his 15 years as a crime scene investigator, he excavated at least 500 secret graves there, sometimes under the surveillance of drug cartels.
“The lookout rides a motorcycle without a license plate, turns off the lights, and says,’You have two hours to finish, otherwise,'” he said.
When this happened, he had no choice but to scoop the contents of the cemetery onto a tarp, throw it into the truck, and then return to the laboratory to complete the work.
In recent years, people have become increasingly aware that many missing persons may be detained by the government—their bodies are scattered among tens of thousands of corpses, and the corpses pass through the morgue without being identified, and then are buried in ordinary graves. . The Mexican authorities vowed to name the human remains in their care.
This is why Robles and 23 other Mexican crime scene investigators, forensic archaeologists, and morgue workers spent five days last month at the University of Tennessee Center for Forensic Anthropology, a world-renowned research center , Better known as the corpse farm.
For more than forty years, researchers on the farm have been burning donated bodies, immersing them in water, breaking their bones, rolling them on the carpet, and then leaving them in the trunk of the car — all of them To learn more about how the corpse decomposes under different conditions.
Usually, when they receive tourists on the farm—a 3-acre sloping forest scattered with about 100 corpses in various decomposing states—the researchers will warn them.
Take a deep breath, director Dawnie Wolfe Steadman told them. If you think you might faint, sit on the ground.
Mexican tourists who lack training but are inexperienced do not need such warnings.
In 1977, forensic anthropologist William Bass was summoned to a cemetery in Franklin, Tennessee, where the police found what they believed was a victim of a recent murder.
Bass came to the same conclusion. Based on the condition of the body, it is estimated that the man has been dead for less than a year. He has been away for more than a century.
The body was originally the body of a Confederate soldier who died in the Battle of Nashville in 1864. In order to dig out anything of value, the tomb raiders took the body from the cast iron coffin that prevented it from decay.
For Buss, this is a transformative moment. He realized that science knows very little about how the body breaks down.
Soon, the University of Tennessee where he worked gave him an old garbage dump behind the medical school for experiments on donated corpses. After community protests broke out—”This made us sick” read a picket sign—the university fenced the area with barbed wire.
For many years, Buss and his researchers have remained obscured. In 1994, crime writer Patricia Cornwell published “The Body Farm,” a thriller inspired by the facility that earned it fame and a new nickname.
Today, more than 5,000 people have registered to donate their bodies after death. Researchers on the farm regularly serve as expert witnesses in murder trials and provide training for the FBI.
A few years ago, when the US government asked if it could start sending a Mexican team to the farm to study forensic excavation, the researchers quickly realized that they had to adjust their typical curriculum.
In short, Mexican investigators work in some of the coldest and most challenging conditions in the world.
“In a grave, you might find three heads and five limbs,” Sandra Macías Gutiérrez, a morgue worker from Colima, takes a break during the day Shi said while eating pizza and soda. “Drug dealers like to mutilate the bodies they have killed so that they are truly illegible.”
Since then President Felipe Calderón declared war on drug cartels in 2006, killings and missing persons surged, many parts of her country have been in a state of instability. The perpetrators—sometimes drug lords, sometimes corrupt policemen—started to create more brutal forms of murder.
Many Mexicans associate the drug war with the United States, not only because Americans have a large appetite for illegal drugs, but also because of the large number of them. firearms The spread of the South Vietnamese border, but also because the sharp increase in violence coincides with a controversial and costly cross-border security partnership called the Merida Initiative.
At the request of Mexican President Andrés Manuel López Obrador, he stated that the militant approach to drug trafficking has turned Mexico into a “cemetery.” New bilateral agreement Under negotiation.
U.S. officials say they will reduce their focus on strengthening the Mexican military and adopt a “holistic” approach to public safety—targeting gun dealers, funding drug treatment, and supporting more forensic training programs, such as bringing Mexicans to Tennessee That project in the state.
Tensions in recent years have made U.S.-Mexico relations tense at the highest level-including claim López Obrador claimed that the United States fabricated a drug case against the former Secretary of Defense of Mexico — it did not exist on the farm.
The students and their teachers are connected by their love of bones, and once squeezed around a group of ribs. The owner of the ribs suffered from a rare disease that caused parts of them to fuse together.
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They expressed sympathy for the popular TV show “Crime Scene Investigation: Crime Scene Investigation”, and they agreed that this triggered inaccurate expectations for the speed of forensic investigations.
The students spent the first two days in class, each morning sitting in a quaint ballroom of the Hilton Hotel in downtown Knoxville and giving a few hours of lectures.
They cover decomposition science and forensic entomology, and learn how to estimate the time of death based on the presence of insects. With the help of a Spanish interpreter, they listened carefully to the lecturer explaining the best way to retrieve evidence when the body was burned.
By the third day, they were ready to enter the dirt. They climbed into the van and crossed the town to the Body Farm.
After putting on fluffy white protective clothing and blue short boots, they walked on the field. Some of the corpses they passed by were made into mummies with leathery skin on their ribs. The others are still covered in black meat. Most of their hands and feet are covered with red plastic nets to protect them from hungry raccoons wandering here at night.
The cool and humid air means that the smell of decay is much less than in the hot summer.
The Mexicans are divided into four teams, and each team will dig a mock grave in the next few days.
For a typical course, the researcher would bury a complete body. But this time, in order to replicate the common situation in Mexico, they prepared a more complicated tomb, dismantled several skeletons, and buried them together with various evidences.
In a cemetery, next to the wooden gallows that researchers sometimes use to simulate hangings, several students quickly built a rectangular grid using wooden stakes and rope. Then they began to deliberately remove the soil, finally revealing a necklace, then a pistol, and finally what appeared to be a femur.
Several people were lying on the ground, sweeping the floor with their fingers and a small brush. Every time they exposed a new layer—the deepest one was about 4 feet—they stopped to draw a map and take a photo.
“We want to preserve the spatial relationship between the different evidence and the corpse,” said Joanne Devlin, deputy director of the farm, who explained that keeping the specific timeline of buried objects is critical to the establishment of a case in the future.
The Mexicans shared their own secrets.
Isaac Aquino Toledo, 43, used small stakes to fix evidence at work. Devlin believes this unusual technique is a genius.
Aquino, a forensic anthropologist in Hidalgo State, said: “Sometimes I find the footprint of a shoe, and then I find the same shoe on the victim.” “Usually the murderer told the victim to dig his own grave. ”
Later, he sighed while digging: “I hope there is a better way to remove these dirt.”
“We need a forensic dust collector,” Devlin said. “Invent one! You can retire!”
While teaching best practices, the researchers also showed some 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 they can approximate every bone in the grave by drawing them on a grid. Instead of measuring them.
In another cemetery, Carolina Montes, a forensic investigator from Tepic, western Mexico, is sifting the soil through a sieve.
She lifted up a small gray-white object that looked like a pebbles.
“Is it cartilage?” a friend asked.
“I think it’s a tooth,” Montes said, putting it in a bag of evidence.
Montes, 26, said that most forensic training programs in Mexico don’t teach much about excavation, and people mostly learn it at work. She found that digging a mock grave on a corpse farm is much easier than working at home.
“The tomb is not very deep, and the dirt is easy to dig through,” she said. “We are used to graves with 10 people inside.”
When her students finished their homework, one of the teachers, Lee Meadows Jantz, put the bones they recovered on the blue tarp. They will be washed, boxed and stored along with approximately 1,600 other bones for future research.
Then she asked her team a question: “Have you buried a body?”
Several people laughed——until they realized she was serious.
This is the ceremony performed at the end of most Body Farm training courses. Meadows Jantz has a partially decomposed body waiting, wrapped in a tarp, ready to be placed in a simulated grave.
The Mexicans buried it under a barren honeysuckle along with some evidence. “Throw another shoe!” one shouted.
In spring, honeysuckle blooms with white flowers. At the end of summer, it will turn dark red. After a few seasons, the corpse will turn into bones-clues that other students can dig.
At the graduation ceremony held at the hotel that afternoon, the director thanked the students and told them: “I think we have learned a lot from you.”
Everyone got a small bag containing trowels, brushes and other trade tools-these things are in short supply in the country.
Usually, Mexican forensic investigators must purchase supplies themselves because their department is underfunded. Sometimes tools are purchased collectively by local families looking for relatives.
this collectiveThe authorities were reminded of possible grave locations. They often stood guard during the excavation process, praying loudly that their son or daughter would be found, even if they were afraid of the result. It is not uncommon for investigators to work in the wailing of mothers.
“It’s very painful,” Montes said. “But I do this work to help people return to their homes.”
How to deal with these emotions is not taught by Body Farm.
Cecilia Sanchez of The Times Mexico City branch contributed to this report.