SAN MARCOS - Daniel Wescott spends his days surrounded by death - skeletons on shelves, leathery corpses in the grass and rotund bodies rotting under the bright Texas sun. It's all part of his standard workweek.

Wescott is in charge of the nation's largest body farm, a sprawling 26-acre research space affiliated with Texas State University, where scientists can study decay out in the wild. It can sound a bit morbid, and, perhaps, bizarre, but since the founding of the Freeman Center body farm - announced 10 years ago this month - researchers have come a long way in understanding how human remains decompose and what that means for solving crimes involving dead bodies.

For instance, when the Forensic Research Anthropology Facility opened, it was difficult to figure out if someone was Hispanic by just analyzing their bones. And the time of death couldn't be determined by analyzing microbes on the skin of a corpse. Ten years and 500-some bodies later, it's a different story.

Today, there's a steady stream of new research coming out of San Marcos. The facility's lab is settling into its new quarters following an August upgrade and significant expansion, while Wescott is in his seventh year at the helm of what could loosely be called the country's largest death lab.

"I've always been interested in dead things," he said. "But it took me a while to get to this point."

The Kansas native was once a cabinetmaker, but shifted careers after going back to school at age 26 - initially for engineering.

"One day, the professor said that somebody brought in a skeleton and did anyone want to look at it, and so I did," he said. "And the next day I changed my major."

Now, studying bones is his specialty. "I do a lot of bone biomechanics. What I'm really interested in is whether you can reconstruct someone's activity patterns and behaviors from their skeleton."

The clues lie in subtleties like how the honeycomblike structures inside the bones compress over time in response to repeated stresses and pressures. For example, obesity can impact the way a person walks, pushing the legs farther apart and putting more pressure on the inner thighs. After death, that shows up in bone analyses when the structures on one side of the bone are aligned differently than on the other side.

A sedentary lifestyle is reflected in bones that are abnormally thin, not built up by movement and pressure.

The bones of long-distance runners are longer and oval-shaped front-to-back.

But before the bones end up boxed on shelves in the lab where Wescott studies them, they typically start as decaying corpses tucked away between the weeds in the grassy expanses outside.

Scientific advances

From a distance, it doesn't even look like the bodies are there. Up close, however, tangled in the grass and weeds, cages jut up out of the plant life, enclosing corpses so scavenging creatures can't get to them.

Some remains are stowed under tarps or tires to study decay in different conditions. Some are buried underground, others tied up or prepared in specific ways in an attempt to replicate ancient burial rituals. Many have "death rings" around them - outlines where liquified organs have leaked out and killed off the surrounding grass.

But some are just bones, intentionally left out without any caging in order to figure out how far and quickly vultures will scatter remains, a key piece of information to know when marking off the perimeter of a crime scene.

On any given day, the farm boasts dozens of bodies in varying stages of decay. And though the death fields aren't open to the public, they attract a variety of researchers from across the country and internationally.

Scientists come in and sample the dirt. Entomologists come in to check out the bugs. Botanists look at the plants.

The lab also trains cadaver dogs, helps identify migrants found dead near the southern border and helps first responders fine-tune their use of hyper-spectral imaging drones to locate human remains.

A lot of the findings are crime-centric, but the lab's work is also helpful in other realms. Public health experts can learn more about the harms of decaying organisms and cemetery planners can find out more about how decay impacts the soil.

"We just know so little about how human remains decompose that having that facility and that location is a priceless asset," said David Carter, an associate professor of forensic science at Chaminade University of Honolulu. "You really can't overstate how valuable their data are."

Nothing but the truth

The body farm helps scientists discover some truths about decay. The data also dispels some conventional wisdom, such as the belief that all dead bodies bloat.

"We have some pretty good evidence that's not true," Wescott said.

People have been dying for a long time - but that little black pearl of knowledge about what happens afterward is fairly new.

"It has more to do with season," Wescott said. "Sure, every body we have out here in the middle of the summer goes through bloat, but we don't know that's true in the winter."

Other factors - like if someone was on strong antibiotics just before death - could impact bloating as well.

Another piece of conventional death wisdom overturned by Wescott's work: Dry conditions make mummies. It turns out that isn't always true, either. At the San Marcos site, for instance, some of the bodies are mummified - even though it's not a particularly arid climate.

"Here, it looks far more like it has to do with the intensity of the sun," Wescott said. "The more radiation, the more desiccation."

The lab's work has also challenged conventional wisdom in other ways. Last year, researchers there made waves when they spotted a deer munching on human bones - a gruesome first that sparked incredulous headlines.

It may all seem a bit esoteric, the stuff of a death-obsessive's dreams. But the findings in San Marcos have immense practical applications that can impact the living - especially those accused of crimes.

"What I'm concerned about is that if we convict somebody, we convict them on fair evidence," Wescott said. And part of that evidence includes knowing when they died.

Over the past decade, studies using skin samples from bodies at the San Marcos site have helped scientists hone in on more exact times of death for days-old dead bodies.

"What we're looking at is the unseen witness, the microbes naturally associated with your body," said Jeff Tomberlin, a Texas A&M University entomologist who has done some of his research at the body farm.

"Once you die, the microbial community will change, and those changes can be critical for determining when somebody died," he said. "That was not possible with microbes 10 years ago."