Texas Research Advancing Study Of Human Decomposition To Identify Deceased Migrants


Texas forensic researchers
Lorne Matalon

Kate Spradley in her lab in San Marcos, Texas. She holds a box containing the remains of a Salvadoran man who she helped identify years after the man had died after entering the U.S. and attempting to evade a U.S. Border Patrol checkpoint.

SAN MARCOS, Texas — Brooks County, Texas — 70 miles north of the U.S.- Mexico border — has seen at least 365 migrant deaths since 2011.

Forensic anthropologists in Texas and Arizona are working to identify these migrants and repatriate their remains.

Behind an electronic gate accessed by a key card on a bucolic farm in central Texas, 100 cadavers donated for research by U.S. citizens lie on the ground in different stages of decomposition.

Forensic anthropologist Kate Spradley heads a relatively new project called Operation ID at Texas State University’s Forensic Anthropology Center.

“When someone dies on U.S. soil, it is our responsibility to identify that person,” she said while walking in the shade where cadavers lay on the ground, protected by metal screens.

Specifically, Spradley collects data on the rate of decay on these cadavers. It’s part of her research in determining a migrant’s time of death.

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“Most of the bodies disposed of in a clandestine manner in this part of Texas, it’s usually on the surface,” she noted.

“It’s very hard to dig a burial there. So knowing how bodies decompose on the surface is very important.”

Brooks County is not on the border. But it does have a U.S. Border Patrol checkpoint at Falfurrias, Texas.

Human smugglers drive migrants to just south of the checkpoint. Migrants then walk miles around it. It takes several days.

Many die in merciless heat. It’s Spradley’s mission to identify them after their bodies are brought here.

“Sometimes when I talk to people about what I do, they will tell me, ’Well why don’t you just send them back home.’ But we don’t know where home is. That’s what we’re trying to figure out.” she said.

Spradley collaborates frequently with Hailey Duecker. She’s the forensic investigator at the Brooks County Sheriff’s Office.

“One of the first things we ask people who report their loved one missing is when was the last time they had contact with them. When was the last time they knew the individual was alive,” she said.

Duecker added that studying the rate of human decay on donated cadavers in different environments here – shade, sun, under trees or nestled in the grass – can help answer that question.

“Knowing how how fast a body can decompose in a specific environment is going to tell us a lot, like if we find a set of remains, who we can match them to based on the date of last contact.”

Duecker says the cadaver research is an asset in both solving cold cases in ongoing criminal investigations and in identifying migrants.

Kate Spradley agrees.

She explained how plant growth around cadavers provides clues for investigators.  We were standing in front of a group of cadavers lying under protective metal screens.

“If you notice (where the cadavers are placed) the vegetation is taller than the surrounding vegetation,” she pointed out.

“So the volatile fatty acids initially when they decompose on the surface, they will oftentimes kill the vegetation. But whenever time it will enrich and you will get vegetation that’s even taller,” she said.

“So those are some the things that you look for if you’re out looking for clandestine remains.”

Because Brooks County is not on the border, it gets no federal funding to identify dead migrants.

The county foots the bill, amounting to hundreds of thousands of dollars per year.

Bodies are found, personal effects and identifying features are catalogued, and then the bodies are buried.

When funding allows, bodies are exhumed for possible identification. Right now investigators are waiting to analyze the remains of 123 unidentified migrants.

Among Spradley’s tools to solve the mystery – who were these people – are vultures.

“Texas has a huge vulture population because of the cattle industry,” she said.

And so some of the donated cadavers are deliberately exposed outside – unprotected – the way migrants are found.

“What we’ve learned is that vultures, once they start to consume a body, it takes about four to five hours to render them to a skeleton.”

And Spradley says understanding how vultures devour a body has changed the way a newly discovered skeleton is analyzed.

“We’ve noticed kind of what we call taphonomic signatures, broken ribs, the pecking out of some of the small, delicate bones in the eye orbit,” she said.

“And those tell us that a vulture has been at the scene. And that’s going impact our time-of-death-estimate. We’ll know that it happened much faster.”

For help in identifications, Spradley collaborates with colleagues in Arizona.

“If a family in Mexico or Honduras is missing someone that entered the United States, they can’t call law enforcement and file a Missing Persons report because they are not a U.S. citizen. So the Colibri Center for Human Rights will take the Missing Persons report.”

The Colibri Center is in Tucson, in Pima County. Its investigators are embedded in the Pima County Office of the Medical Examiner.

“To contrast Arizona and Texas, in Arizona, the Pima County Office of the Medical Examiner serves the entire (Arizona) border. So a body is found, it’s brought to a medical examiner’s office. And it gets a full chance at identification,” Spradley explained.

“In Texas, there are so many counties along the border and so few medical examiners that not everybody makes it to a medical examiner’s office. Right now we’re trying to figure out how many people die along the Texas border.

“We have no idea because there’s no centralized reporting system,” Spradely said.

And that means, in Texas, a full accounting of the number of people who die each year attempting to enter the U.S. from Mexico and beyond is next to impossible to compile.


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