As bodies decompose, their types and numbers of bugs and bacteria change. Deciphering the clues they provide could mean the difference between a closed case and an unsolved murder.
Michigan State University is using a more than $866,000 U.S. Department of Justice grant to help Detroit death-scene investigators examine these changing populations. The microbial communities may provide crucial details such as geographical location of death, gender, race, socioeconomic relations and more, said Eric Benbow, MSU entomologist and osteopathic medical specialist.
“We know how important the human microbiome, the bacteria, fungi and other microorganisms that live in your body, is to human health,” he said. “We, and other researchers, hypothesize that these communities play an equally important role in postmortem. We are the first university to work directly with medical examiners in this capacity, pioneering the collection of novel human microbiome information at the scene of death or during autopsy.”
Through the grant, which is being shared with Mississippi State University, MSU will work directly with the Wayne County Medical Examiners Office. When examiners are contacted to investigate a death scene, they will gather samples and use swab kits provided by MSU. The kits are then sent to MSU to be processed and then sequenced in a campus genomics lab.
Along with aiding the investigators with their cases, the researchers will be testing the viability of the fledgling approach and techniques, which traditionally have been relegated to bodies that have been donated to science.
“Donated bodies don’t work as well because they have been handled, cooled or frozen while being transported. This can influence and change the microbial communities,” said Benbow, an MSU AgBioResearch scientist. “Working with a large, metropolitan examiners office allows us to participate in investigations as they happen. It’s real-world, translational and real-time and may have immediate relevance and benefits.”
Benbow’s efforts are already seeing positive results. His lab was recently contacted to investigate a case unrelated to the Detroit partnership. His team gathered samples from the scene, in which the cause and time of death, as well as the suspect, were already known.
Knowing those key facts will allow Benbow to validate the data reflected by the bugs and bacteria found on and in the body. Because so many major facts were already established, he can glean better insights of the “microbial clock” and calibrate his tools to examine these communities.
“Imagine your microbial clock in terms of a town filled with different people with different jobs and activities; towns evolve with time, reflecting changes associated with the larger environment around them,” Benbow said. “When you’re living, you have a distinct community of bacteria. When you die and blood stops flowing that causes some microbes to flourish and others to perish. Two days later, those communities are different; seven days later, those communities have changed again.”
Through the Detroit partnership, Benbow will create a repository of the samples and data that he’s acquired from these microbial communities. By publicly sharing the findings, other scientists and cities can benefit from this novel approach.
Many of the techniques that Benbow is helping pioneer will be featured in a book he is editing. “Forensic Entomology: International Dimensions and Frontiers,” will publish this spring and include authors from around the world sharing how their research can help advance the field of forensic science.