Jeffery K. Tomberlin, a professor at Texas A&M University, presented an evening lecture called “Harvesting Death for Humanity’s Benefit: Linking Microbial Communication with Insect Behavior” how his research in entomology has assisted law enforcement in determining the circumstances of homicides and other deaths on Tuesday.
Tomberlin’s lecture in Waters Hall laid out how the decomposition process is a key determinant in judging the circumstances around postmortem forensics and how the colonization of insects is often a catalyst for decomposition.
Tomberlin said the decomposition process is broken down into two primary intervals.
“Between the pre-colonization and post-colonization of insects, most research is focused on post-colonization, or what happens with the remains over time when the insects are all gone.” Tomberlin said.
This, Tomberlin said, led him to dissect periods of insect activity before they colonize in the decomposition process. This research uncovered certain pre-colonization behaviors that varied based off of various circumstances that had not been previously considered in insect such research.
Tomberlin’s research has led him to assist in various cases that involved decomposition of human corpses.
Tomberlin, who earned his Ph.D in entomology from the University of Georgia, received his first ever case as a forensic entomologist from investigators in Gainesville, Georgia, in 1998.
“I believe that I have won the lottery of entomology with this case, because out of the millions of insects identified in the world, I had studied one insect in my Ph.D,” Tomberlin said. “And when they showed me in the case, I was like, ‘Yes I know that insect.'”
The insect that was found on the bodies in his first case was the black soldier fly, which had been previously suspected to not colonize human remains unless it had already been decomposing for 20 to 30 days.
“So what we knew was that the person was last seen Thanksgiving Day and the body was found in February,” Tomberlin said. “It had also been determined that these flies would not colonize without temperatures in the 80 degree range.”
By determining the temperature range of northern Georgia that year after November was between 45 to 60 degrees, Tomberlin concluded that the colonization of the body must have happened earlier than 20 to 30 days after decomposition began.
Through studying the black soldier fly under different behavior variables, Tomberlin was able to confirm that under certain circumstances, the fly would colonize earlier than previously thought. This allowed investigators to date the time of death within a week of the Thanksgiving holiday, which led them to track down a suspect, he said.
Tomberlin emphasized that being conscious of the details in the investigation site’s environment can reveal different variables in insect biology and behavior.
“These details can be extremely critical in the interpretation of entomological evidence.” Tomberlin said.
Tomberlin’s lab is currently working on in collaboration with Mississippi State on a project pertaining to the causes and ecological effects of “mass mortality events” in certain communities of animals around the world.