Tiny moss plants, often overlooked, are proving valuable in criminal investigations by revealing precise locations of crimes. A new study reviews 150 years of cases where bryophytes like moss provided key evidence, including a 2011 case in Michigan that located a buried child. Researchers urge law enforcement to consider these small plants as silent witnesses.
Moss may seem unremarkable, growing low to the ground in damp, shaded spots, but its sensitivity to specific micro-environments makes it a powerful forensic tool. Different species thrive in unique conditions, allowing even tiny fragments to pinpoint where a person or object has been. A study published in Forensic Sciences Research compiles evidence from over a century of cases, showing how bryophytes—simple plants without true roots, stems, or leaves—have aided investigations worldwide.
The review, led by Matt von Konrat, head of botanical collections at the Field Museum in Chicago, began during a 2024 internship by Jenna Merkel, a forensic science master's student at George Washington University. They examined scientific literature spanning 150 years and found limited but impactful uses. The earliest case, from 1929, used moss growth on a skeleton to estimate time of death. Since then, at least ten more instances have been documented in Finland, Sweden, Italy, China, and the United States, providing clues on timing, location, or circumstances.
A standout example from 2011 involved the murder of a baby girl named Kate by her father in northern Michigan. After he buried her body and gave only a vague location, police found microscopic plant fragments on his shoes. In 2013, von Konrat and a team of botanists surveyed the area, cataloging mosses, grasses, and trees across seven counties. The moss evidence narrowed the search to about 50 square feet, which the father later confirmed as the burial site. "There are hundreds of species of moss and dozens of species of grasses and trees living in that area," von Konrat noted. "But based on the bits of moss, we knew what sort of micro-habitat we were looking for."
Bryophytes absorb water and nutrients directly from their surroundings, making them ideal indicators of local conditions. "Because they're so small, they have all sorts of microhabitats—even if an area overall seems to be one sort of habitat, they can find a spot that works for them," von Konrat explained. The researchers emphasize that investigators often miss this evidence due to lack of awareness. "With our paper, we wanted to highlight the significance of botanical evidence, because chances are, investigators are simply overlooking it," von Konrat said. Merkel added, "Plants, and specifically bryophytes, represent an overlooked yet powerful source of forensic evidence that can help investigators link people, places, and events."
By raising awareness of forensic botany, the study aims to equip law enforcement better and bring closure to affected families.