Research Resources
Written by Dale Garrison   

LOCATED on Texas ranch land about halfway between Austin and San Antonio, the Forensic Anthropology Research Facility (FARF) is one of five “body farms” in the United States. It’s also a place where the future of forensics is being revealed.

Operated by Texas State University, FARF is the largest outdoor human decomposition research laboratory in the world. Part of the university’s 3,500-acre Freeman Ranch, it now hosts studies that are examining everything from previously unknown details of microbial activity on human remains to the use of drones for locating bodies.

All of this takes place under the supervision of Associate Professor Dr. Daniel Wescott, director of Texas State’s Forensic Anthropology Center. Many of the school’s master’s students conducting studies are in his program and, in several cases, he is actively involved in their work. He also oversees the outdoor lab and two indoor labs used by university students and visiting researchers. Their work, and the potential for impact on forensic science, is significant and diverse.

“We have everything from chemists to soil scientists to microbiologists, and now we’re starting to do some imaging and getting computer scientists,” Wescott said. “My hope is to make this a very interdisciplinary effort, where we’re all working toward the same goal.”

The center opened in 2008, but the pace of research expanded dramatically about the time Wescott came in 2011. One reason is the growing number of donated bodies. The first few years, only ten bodies a year were contributed. Because of greater awareness and the Texas Anatomical Gift Act, that number leapt to 66 in 2013 and is on pace to reach 75 this year. The center is also adding to its capabilities with equipment such as a recently acquired micro-CT system, as well as a 3D printer, allowing researchers to target a wider range of work. The result is more work in more areas.

Wescott noted one example: “Our collection of skeletons is now big enough that they can be used for studies. People are going to start coming to do research just on skeletons and that’s going to be interesting.”
Some of the procedures at FARF provide advantages to researchers looking to learn more about pathology, human decomposition, and more. Again, using skeletons as an example, remains donated to the center are usually accompanied with photos of the living person. This provides forensic artists or students a way to check on the accuracy of their attempts to create a lifelike rendering from a skull.

Timing is Everything

Several efforts at the center focus on determining the time of death, and this area includes some of the most exciting research of all. “In general, the work is moving toward refining several methods to where we can give a pretty accurate estimation of time of death, rather than just an ‘guesstimation,’” Wescott said. “And using the micro-CT scanner and high-resolution scanning, we have a number of studies that we’re starting that will help examine knife and bullet wounds, something that’s not easy or is even impossible otherwise.”

Research by Dr. Jeffery K. Tomberlin is a good example of these advances. Tomberlin, who is lab director at the Forensic Laboratory for Investigative Entomological Sciences (FLIES) at Texas A&M University, recently posted a report for which he was the lead author: “Development and Validation of Standard Operating Procedures for Measuring Microbial Populations for Estimating Postmortem Interval”. Like others working at FARF, he sees his work as only a beginning.

“Microbes hold a tremendous amount of potential for very accurate time of death estimates up to a year or longer after the event,” he said. “We have markers to nail down, but they have a lot to offer with time of death and beyond.”

One step in moving this work forward will be verifying common microbes among unrelated remains, and measuring the variation in microbial activity in different regions. “San Marcos (the location of FARF) is different from Houston or Tennessee,” Tomberlin said. “Answering those questions will take more study and more coordination between different studies.” Such collaboration is already underway, including an effort that involves professionals from Texas A&M, Michigan State, and the U.S. Department of Agriculture.

All of this also helps add to the growing cadre of trained professionals qualified to work in these specialized fields. “The thing that’s really nice about this is training new researchers,” Tomberlin concluded. “Facilities like this allow us to train more researchers, so we have new people able to continue these efforts.”

Jacqueline A. Aitkenhead-Peterson and her work offer another good example. An associate professor of soil chemistry at Texas A&M, she is completing a study to refine post-mortem interval (PMI) estimates and will publish the findings in a book next spring, International Dimensions and Frontiers in Forensic Entomology. The chapter for which she is lead author, “Application of soil chemistry in forensic entomology,” examines changes in soil composition in the “island” surrounding a decomposing body. Using infrared spectroscopy, she has documented a steady, measurable rate that would be useful for several fields, including law enforcement.

“Since I’ve been working at the body farm, I have been contacted by various prosecutors and law enforcement training officers on where they should take soil samples,” Aitkenhead-Peterson noted. “That’s really snowballed, too, in terms of analyzing soils from crime scenes and comparing with soil from suspects.”

With spectroscopy, she believes up to a 98-percent match will soon be possible. “It is early,” she cautioned. “Your data needs to be peer-reviewed and published before it’s allowable in court. But I tell law enforcement officers whenever I get the opportunity that if they have a case, collect soil! The more opportunity we get to devise methods, the better.”

Inside and Out

Research projects conducted by Dr. Gulnaz Javan and doctoral student Sheree Finley focus on microbial activity inside and outside a decomposing body. Sampling the microorganisms found in the soil beneath a decomposing body (above), for example, could provide a microbial gene signature that may help determine post-mortem interval. —Photo courtesy Dr. Gulnaz Javan

While many studies examine what is going on with a deceased body, some of the work by Dr. Gulnaz Javan and Sheree Finley, a Ph.D. student in microbiology, takes a different angle. Javan has traveled from her home base at Alabama State University’s Forensic Science Program to pursue her work, which also involves looking for better means to determine post-mortem interval. A significant part of her research is focusing on microbial activity within the body of the deceased. Finley’s work focuses on microorganisms found in the soil beneath a decomposing body.

“The outcome of these studies will lead to a conceptual framework that will help crime scene investigators with the estimation of PMI,” Javan said. “The metagenomic analysis of soil genomes will reveal a PMI-specific, microbial gene signature, and the observed trends of microbial abundances will be used to construct post-mortem microbial clocks.”

Like much of the work at FARF, Javan’s research will bring new knowledge and forensic capabilities to law enforcement. “Many scientists are focusing on external aspects, but I’m looking at the decomposition of internal organs,” Javan said. “We have lots of unanswered questions which need to be addressed.”

Javan’s efforts also illustrate other aspects of work at FARF: a widespread need for significant financial support. The recent award for Alabama State University Forensic Science Program of a $200,000 grant from the National Science Foundation was a windfall to the study. “It allows us to move forward,” she said.

While all research at FARF is relatively high-tech, some projects are especially notable. Kelsee Hentschel’s work is a good example. One of several students who conduct research at FARF, she is pursuing her master’s degree and is also a research assistant at the Forensic Anthropology Center at Texas State. Her novel research uses geographic information systems (GIS) in a way that is almost like something from a science fiction story. Usually applied to creating detailed maps for city zoning, GIS spatial plotting can also be applied to smaller areas such as bone surfaces, including fractures. When the technique is finalized, just one impact her research will bring is a huge increase in quantifiable measurement of fractures in the courtroom.

“I looked at how the fracture surface changed throughout the post-mortem interval. I found that fractures created later in the post-mortem interval tended to have smoother surfaces and, with GIS, we can use statistics to quantify that,” she said. “I can actually use statistics to quantify the changes in the fracture surface and then use those statistics in testimony. That’s hard to argue with.”

This work starts with the fact that living bones have more collagen, which makes them more flexible. Hentschel is quantifying differences between a bone break made before death and one after, such as one made by animals, disturbances in the environment, or other factors.

“Bone will not snap the same way after death,” she explained. “When bone is living, it tends to fracture at different angles at the fracture edge. Even the outline of the fracture changes as bones dry out. With these tools, we can measure those differences to microscopic levels.” That microscopic examination can even reveal differences from earlier, less detailed images.

Those changes in bone and fractures also occur at different rates, raising another new area of study. “When I broke the changes into early, middle, and late stage, the differences were significant,” she said.

And, once again, this work is only a beginning. “This particular project definitely needs validation studies,” Hentschel added. “Eventually, I would like someone to be able to give me a bone, scan it, and then I see where it falls in terms of early or late by looking at the outcome. On the same note, someone could come up with more tools. GIS is just a start—there are a million tools out there that we could apply, and a lot of them could better our methods.”

Up in the Air

Louisiana State University Ph.D. candidate Lauren Pharr studies the effects of vulture scavenging on human remains. This Black Vulture has been fitted with a tracking device to help identify movements of the scavengers, topography preferences, and feeding patterns. —Photo courtesy Lauren Pharr

One of the most unusual efforts at FARF may also be one of the most visible. Lauren Pharr is a Ph.D. candidate at Louisiana State University, who is studying vulture scavenging. What she has learned about the birds is directly relevant to outdoor death investigations. Among her most notable findings: the scavenging birds leave down feathers that have a measurable lifespan; this can help determine time since scavenging with much accuracy.

“After two weeks, it’s hard to recognize them,” she said of the down feathers. “That can give you a very good starting point almost immediately.” Knowing the time since vulture scavenging and the fact that vultures prefer fresh decay, one can readily infer whether the death was recent or not.

She’s also learned a great deal about the large birds, including just how picky they are about location, by monitoring vultures’ hourly movements via GPS tracking. Using funds provided by the National Science Foundation, Pharr attached tracking devices to FARF vultures. She has been able to isolate probable scavenging locations and is determining which environmental characteristics are associated with vulture scavenging.

“When police officers contact me about possible vulture-scavenged remains, the first thing I ask is, ‘Is the site near fresh water?’” Pharr explained. “Vultures appear to favor areas near water. The GPS data also indicates that the topography of the land plays a role in where vultures will travel.”

The aim of Pharr’s research is to identify other geographic factors police officers can use as a starting point for when to consider vulture scavenging. As most investigators know, when determining cause of death and post-mortem injuries, also determining “what did what” before or after death is important and difficult. “We can often tell that some animal has been there, but was it a cat, dog, or vulture?” Pharr said. “The most visible differences are that vultures will leave a very clean skeleton, but they cannot chew or gnaw bone.”

Much of the research at FARF is a little like the tip of an iceberg, with years of research and preparation underlying the work at the center or in one of the two nearby, indoor laboratories. In Pharr’s case, the research involved even more groundwork; she first spent almost four years learning about vultures and their habits.

“What’s surprised me the most is that they are very social and have a definite social hierarchy,” she said. “They’re actually quite intelligent but apparently have a weakness for hog guts.” This last personality trait helped her overcome an initial obstacle: trapping vultures to tag and study them.

“It took ten months to successfully trap one, a vulture I named Bubba Bird,” she recalled. “But when I finally got him, I had to drive Bubba to a housing pen at FARF. The pen had a chicken wire roof, so once Bubba was inside it was only a few minutes before all of his vulture friends were walking around the pen trying to get inside. It was amazing to see.”

Pharr hopes to receive her doctorate late this year and plans to continue the work. “I would like to investigate vulture behavior in different environments,” she said. “And we should examine differences between scavenging of clothed versus unclothed subjects, in wooded versus open areas. Vultures have such a tremendous impact on post-mortem investigation, but we don’t know that much about them.”

Her ambition is to communicate her findings to those directly involved in legal work. “I would like to promote some of these ideas for recognizing vulture scavenging to law enforcement,” she explained. “We still have more to learn, but when officers are at a body site, this information could give them a starting point.”

High Tech Flight

Marilyn Isaacks’ research looks at the usefulness of aerial drones equipped with near-infrared cameras for locating human remains in a large, open area. The images above were captured on the same day. In the naked-eye photo (left) the large rectangles are cages around body-placement sites at FARF. In the upper right corner, several older placements can also be seen, where all that remains is the cadaver decomposition island (CDI). In the near-infrared image (right), the older CDIs are much darker than the surrounding soil, as are the CDIs of the bodies still under the cages. —Photos courtesy Marilyn Isaacks

Marilyn Isaacks’ work also involves objects that fly, but in her case, it’s aerial drones utilizing video equipment to measure both visible light and near-infrared light. The latter display is similar to that of night-vision equipment. Unlike many of the studies at FARF, hers focuses not on measuring post-mortem time intervals or other factors, but in finding bodies in the first place.

“It’s an idea that Dr. Wescott proposed,” she explained. “By testing an area where we know there are bodies, we have a control that you normally wouldn’t. We can see what works and what works the best.”

Using monthly flyovers conducted by a nearby, private drone operator, the Texas State University graduate student examined the resulting images in one of the nearby computer laboratories. She quickly found that the difference between visible light and infrared images was dramatic.

“With visible light, you can kind of see where the body sites are,” she noted. “But when you use near-infrared, the body positions show up really well, even after the body has been moved.”

A biological anthropology major, Isaacks sees widespread opportunity for applying the information. Not only are the implications significant for law enforcement, but in other uses such as military investigations.

“This should definitely have forensic application,” she said. “But I would also like to work with the Joint POW/MIA Accounting Command (often referred to as JPAC). There are a lot of applications where this could be very useful.”

The benefits are likely to be dramatic for police work alone. In many cases, law enforcement today must use body-location techniques that have not changed a great deal for decades… or even centuries. “Currently, when there’s a reason to believe a body has been placed somewhere, about all you can do is a line search. But this could create something that can fly over and allow someone to focus right in.”

Dr. Norma Iris Caraballo utilizes solid-phase microextraction and a gas chromatograph-mass spectrometer to analyze the odors given off by decomposing human remains. —Photo courtesy Dr. Norma Iris Caraballo

Research by Dr. Norma Iris Caraballo is also adding to forensic capabilities. Caraballo, who just received her Ph.D. in chemistry with an emphasis in forensic science from Florida International University, recently conducted analysis of odors emanating from decomposing remains.

“I wanted to actually see whether or not the odors change over time,” she explained. “They do. They actually go through distinct stages that we can differentiate.” Caraballo was able to delineate three separate stages of decomposition, although another two remained difficult to distinguish.

Among the biggest surprises was an indication that cadaver dog training may need to include aids at various stages of decomposition. “Dr. Kenneth Furton’s research lab at FIU focuses on detector dogs, so we wanted to try to determine what cadaver dogs smell,” she noted. “There were some surprises. While we were able to distinguish three separate stages of decay based upon their common compounds, we couldn’t find a common odor for skeletonized remains. The amount of some odors present could be so small that our method did not have the capability to detect it; however, we know that cadaver dogs can find skeleton remains.”

While she lives and works in Florida, Caraballo had praise for the Texas research facility and its director, Wescott, with whom she collaborated on her work. Like other researchers, she emphasized that her study is important precisely because it raises more questions.

“One day, we may be able to develop a pseudo-training aid for agencies that don’t have resources,” she said. “There are only a handful of researchers in the world studying the odor released from decomposing remains because getting money to do this research is tough. We need cadaver dogs and training can be difficult because what they use for training aids is otherwise very limited. It’s important that research continues in this area.”

While all of these results are impressive, the best may be yet to come. “We’re seeing so many developments after a relatively short time,” Wescott concluded. “It’s very gratifying and very exciting to be a part of this.”

For More Information

For more information on the Forensic Anthropology Research Facility (FARF), go to:

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