This tiny plant is helping solve crimes
Small plants like moss rarely draw attention. Many species are no wider than an eyelash and typically grow close
Small plants like moss rarely draw attention. Many species are no wider than an eyelash and typically grow close to the ground in damp, shaded environments. Despite their modest appearance, these plants can provide critical evidence in criminal investigations. Scientists experienced this firsthand in 2013, when they were asked to analyze tiny fragments of moss to help determine where a body had been buried. That experience later led the team to publish a study in the journal Forensic Sciences Research, bringing together known cases in which mosses and related plants played a role in solving crimes.
“With our paper, we wanted to highlight the significance of botanical evidence, because chances are, investigators are simply overlooking it because they don’t know what they’re looking at. We’re hoping that our study helps show how important these tiny plants can be,” says Matt von Konrat, Head of Botanical Collections at the Field Museum in Chicago and corresponding author of the paper.
What Makes Moss So Useful in Forensics
Mosses belong to a group of plants known as bryophytes. These plants are among the simplest on Earth and lack true stems, leaves, roots, or seeds. Their structure allows them to absorb water and nutrients directly from their surroundings. This ability helps them survive in wet, shaded, and bog-like environments where many other plants struggle to grow.
Certain bryophyte species are especially sensitive to their environment, and each tends to thrive under very specific 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 in the shade, or in the canopy, or even growing under the grasses,” says von Konrat. “And different types of even smaller organisms can live on those mosses, which can give even further clues This means that mosses can be a valuable tool for forensic scientists looking to confirm details of where a crime took place.”
A 150-Year Look at Moss in Crime Solving
In 2024, Jenna Merkel, then a Master’s degree student in forensic science at George Washington University, began an internship with von Konrat at the Field Museum. “I thought, why don’t we look into writing a review of how bryophytes have been used in forensics?” says von Konrat. Together, they examined 150 years of scientific literature to see how often these plants had appeared in criminal investigations. “So we reviewed 150 years of scientific literature to see how these plants have been used in investigations. Well, it turns out, the answer was, ‘Not that much.'”
The earliest documented case they identified dates back to 1929. In that instance, moss growth on a decomposing skeleton helped investigators estimate how long the individual had been dead. Since then, at least ten additional cases have been reported across Finland, Sweden, Italy, China, and the United States. In each case, bryophytes contributed information about the timing, location, or circumstances of a crime.
The Case That Changed Everything
The paper also includes the first detailed scientific account of a case von Konrat and several co-authors worked on more than ten years ago.
In 2011, a baby girl named Kate was killed by her father, and her body was never immediately located. The father provided police with only a rough idea of where he had buried her in northern Michigan. Investigators also discovered microscopic plant fragments on his shoes. In 2013, von Konrat led a team of botanists and volunteers to survey the region, cataloging grasses, trees, and mosses in search of a location that matched the plant material found on the shoes.
“There are hundreds of species of moss and dozens of species of grasses and trees living in that area,” says von Konrat. “But based on the bits of moss, we knew what sort of micro-habitat we were looking for.” The team narrowed the search from seven counties to a small area of roughly 50 square feet. During a police interview, the father later confirmed that this was the exact location where he had buried his daughter.
Why Forensic Botany Deserves More Attention
The researchers hope their work will encourage greater use of bryophytes in criminal investigations and help bring closure to families affected by violence.
“Plants, and specifically bryophytes, represent an overlooked yet powerful source of forensic evidence that can help investigators link people, places, and events,” says Merkel. “Through this paper, we aim to raise awareness of forensic botany and encourage law enforcement to recognize the value of even the smallest plant fragments during investigations.”
