By Harvey Black
You are called to investigate a body that was discovered on the side of the ski trail Caper at Killington Resort. It was discovered after some hikers noticed a faint odor. When they investigated, they found the body of a woman that was very decomposed.
You are called to investigate another scene in the evening where you find the body of a middle-aged man on the second floor of a house. Upon entering the house, the odor is quite noticeable. The lights do not turn on, so you must use a flashlight. The thermostat dial is set to 70° Fahrenheit.
While these scenarios sound like they come from police murder investigations, they were actual assignments for students in Nancy Miorelli’s forensic entomology course at the University of Georgia in the fall semesters of 2012 and 2013.
“I think it was my favorite out of all the courses,” said Miorelli, who taught the course while she was a graduate student. “I think the subject matter is so fascinating because it’s one of the few examples that I can think of for applied ecology. Knowing how systems interact helps you solve crimes. That being said, my favorite part was creating and completing the case studies. I love writing, I love non-traditional school activities.”
For TV shows such as the CSI franchise, forensic entomology has become a staple. Forensic entomology, to put it succinctly, is applying the knowledge of insects and other arthropods to legal or criminal cases. And the students in her classes learned how to do that.
“When you walk onto a crime scene, you [as a forensic entomologist] know nothing about what happened,” Miorelli said. “All you have is a dead body. So I tried to walk [the students] through the process of asking questions.”
For example, since temperature is a factor in decomposition and the growth of insects, the students would have to get information about temperatures from U.S. Weather Service stations at nearby airports. Students would be able to use such data to understand how insects would change over time.
“It was really cool, just being able to find something that is dead by the side of the road, and based off of what insects [were found] and their stages of life, you can figure out how long something’s been dead. I didn’t know that was a real job,” said former student Heather Stinnet, who now works for a pest control company.
The students also got a firsthand chance to understand how insects do their work on corpses and how forensic research is conducted — not on human ones, but on the remains of euthanized pigs, as you can see in the following short video:
“We had a five-week decompositional study,” Miorelli said. “We euthanized a pig for each of the three groups of students, and put them out in a field. The students collected data every week. They collected maggots out of the dead pig, they had to log the temperature at the crime scene, and they had to record the decompositional stage of the pig.”
The students had to make presentations on what they found, and they did different things to the pigs to make the “crime scene” more realistic.
“Some students chose to clothe it,” said Stinnet. “Some students chose to cover it with debris. One group cut it up into little pieces.”
That field experience was Stinnet’s favorite part of the course.
“They provided three real pigs,” she said. “We got to watch them be euthanized, and then we watched those three pigs decompose. I don’t think there’s any better way to teach than watching what actually happens — even though it smelled awful.”
The fieldwork also appealed to Trey Portier, another student in the class who is now a graduate student studying integrated pest management.
“Instead of just seeing pictures, we got to go out and set up a crime scene with a dead pig and collect insects off of it,” he said. “You could find different types of insects.”
Miorellli also required students to behave like real forensic entomologists.
“I designed case studies for that,” she said. “Each group got a different scenario — for instance, you find a body in the back of a car in a junkyard. What do you do? What questions do you ask? That’s one of the things that was really important to me. When you walk onto a crime scene, you literally know nothing about what happened. All you have is a dead body.”
Miorelli used real locations for the crime scenes, and the students used the temperature data they got from airport weather stations to assess how the insects changed over time.
“That’s what real investigators would have to do,” Miorelli explained.
The students also had to determine when a person died by observing and identifying insect specimens, provided by Miorelli, that would have been found at the crime scene.
Field investigation and analysis is only one part of a forensic entomologist’s job, since the entomologist — who may appear in court — will often have to discuss the findings.
“The forensic entomologist has to both be a good scientist and understand how the insects play a role, and then has to effectively communicate to a jury that may have less than a sixth-grade science education,” Miorelli said.
In the course, the students had to do this in front of a mock jury of other students.
“Intimidating,” is how Stinnet described doing that.
For former student Tae-Young Lee, the mock trial was an important learning experience on how to present information.
“The premise was to stay within the realm I know, rather than speculate,” he said. “I had to stay very, very objective and cold-minded, and stay true to the data I had. If there is something I don’t know, I have to be able to say, ‘I don’t know that.'”
It’s clear that the course benefited both the students and their instructor. The students came away from the course having learned how to solve complicated problems and to communicate their findings, and Miorelli enjoyed guiding them and helping them grow intellectually.
The course will be offered again this fall, although Miorelli won’t be teaching it. Instead, she’ll be volunteering with the Maquipucuna Foundation, working to conserve the rain/cloud forests of Ecuador.
Harvey Black is a freelance science writer. A long-time resident of Madison, Wisconsin, he has written for numerous publications including Environmental Health Perspectives, Scientific American Mind, New Scientist, The Scientist, and the Milwaukee Journal Sentinel.