Deciphering death: The fungi and bacteria that could revolutionize forensics

During the research, 36 human corpses were examined by the scientists. These bodies were from donors who voluntarily consented to their use for research purposes before their deaths. The bodies were situated in unique 'body farms' in three distinct locations: Tennessee, Texas, and Colorado. These locations, characterized by differing climates—temperate, humid, and semi-arid—were geographically far apart.

As detailed by Live Science, experts gathered DNA samples from the deceased's skin and the surrounding soil during the initial 21 days post-mortem. This timespan marks a period of swift and dynamic tissue decay. From these samples, the experts aggregated ample data and used it to sketch a comprehensive picture of the "microbial community", or microbiome, present at each site where the inspected bodies were found.

Intriguingly, regardless of the location, climate, or prevailing season, scientists discovered the same set of approximately 20 specialized microbes decomposing on all 36 bodies. Phys.com mentioned that these microorganisms appeared predictably at specific instances during the 21-day observation period, with insects playing a pivotal role in their appearance.

In the subsequent step, the experts utilized the data gathered during the study along with previous analyses, incorporating machine learning to develop a special tool. This tool can determine the time elapsed since the moment of death with an accuracy of up to three days. While scientists believe their findings could prove invaluable in forensic investigations carried out in various locations and climates, they emphasize that further research is required to enhance the tool.

The objective is for the tool to function in real-world conditions, not just in those manufactured for the study. Bodies are often buried, wrapped in various materials, or stored in water tanks, rendering them less accessible to the insects critical in these studies. In such situations, a body could decompose differently. Hence, it's crucial to ascertain whether similar patterns still emerge.

Prof. David Carter from Chaminade University in Honolulu, who participated in the study, commented: "When we touch on the subject of examining death scenes, there are very few types of physical evidence that you can guarantee will be present at every location. Fingerprints, blood stains, or footage from a camera may not always be available. But the presence of microbes is guaranteed."