Inside the Lab Part 3: UF researchers study decomposition, hidden graves to help crack criminal cases

GAINESVILLE - Florida has soft and sandy soil compared with other states. Scientists at the University of Florida say that makes this a popular state for clandestine graves. 

It’s one of the things they’re researching within a secret lab site in a Gainesville forest, which FOX 35 got to tour exclusively. Their work has helped solve active investigations and cold cases and is even used to research tombs.

A lot of the scientists’ work has to do with finding clandestine graves. 

They get some clues from depressions and mounds, as well as differences in botanical growth. 

Dr. Jason Byrd, a Professor of Medicine at the University of Florida, explained that investigators must learn to look for differences in the growth stage among trees or clusters of species that stick out. Those things are clues that a body may have been buried in that spot. 

"The body is going to impact the environment," explained Dr. Byrd. "It's going to change the pH of the soil. It's going to attract different animal species, different insect species. So it's going to change also the species of plant that you would expect to find."

The digging also disturbs the seed bank and replants seeds, leading to different germination. 

Forensic anthropologists go in with a soil probe if they’re interested in a particular area. That tests how compact the soil is typically, as compared with a site that was disturbed. 

Dr. Byrd demonstrated this tool. As he pressed a metal pole into the ground throughout the woods, he showed how far he could push the tool into the ground, applying a medium amount of pressure. Suddenly, he reached a spot that stuck out.

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• Inside the Lab Part 3: UF researchers study decomposition, hidden graves to help crack criminal cases

"You can see how easy that goes down," he said as the metal tool glided easily into the soil.

Dr. Byrd explained that when someone digs up the earth, it aerates the soil, just like a farmer tilling the land would. Since the soil is less compact, it’s easier to push through. 

If the dirt is easier to pierce in one spot than it is everywhere else throughout the woods, scientists can see that someone may have dug through that area recently. 

If they want to investigate the spot further, they go in with a soil corer to see what the layers of earth look like. In most places, there will be clearly defined layers within the soil. You can see that with the soil corer if it’s been dug up and mixed. 

"We call it stratigraphy," said Dr. Byrd, holding up the corer with an example of dirt that had been dug recently. "You have a little bit of organic matter way down here. So it just shows you that this height has been disturbed."

Finally, they bring out the big guns: ground-penetrating radar.

Dr. Lerah Sutton, the Director of UF’s Forensic Medicine Educational Program, walks around the woods with the tool as it sends radar pulses through the ground.

She calls it the latest and greatest in new tech.

"I think that we could do nonstop research on this topic," said Dr. Sutton. 

Those researchers have bodies buried throughout the forest at different times. They practice burying the bodies in different ways, using specific tools or digging by hand so they can see how the forest grows back. Tracking those trends helps them find clandestine graves.

Dr. Sutton is also the Assistant Director of the Maples Center for Forensic Medicine.  The researchers who frequent the forest also do plenty of work in the Maples Center lab. 

Namely, with maggots. That’s one of Dr. Byrd’s specialties. The bugs reveal information about how long a person has been dead and where the body may have come from.

"You know, we have dumped bodies all the time," said Dr. Byrd. "We have found human remains just dumped on the side of the interstate system here. So, they may not be local cases. And we analyze the insects to determine what part of the country they may have come from."

The maggots also help researchers learn about decomposition in the forest. The bodies come from an anatomical donation program. It’s grown a bit over time. 

The decomposition research on those bodies helps with active investigations and cold cases and is even applied to ancient tombs.

"The smallest details and changes can really change the way that the entire process of decomposition occurs," said Dr. Sutton. "It's critical to determine that time since death so that you can either corroborate or refute the story that a suspect in this case is telling," said Dr. Sutton. 

Things like sun versus shade, if an area is rainy or dry, humidity levels, clothing, depth of the burial, and the type of soil the body is in will all impact how it decomposes. 

"When we get into these real world cases, the more information we've learned in a controlled scientific setting, the more certain we're able to be," said Dr. Sutton.