A moss sample helped investigators prove that cemetery workers had moved human remains and resold burial plots by revealing both the origin and age of the plant evidence.
In 2009, authorities uncovered a major scandal at a cemetery near Chicago. Employees at Burr Oak Cemetery in Alsip, Illinois, were accused of digging up older graves, discarding the remains elsewhere on the property, and then selling the newly emptied plots to other families. When the case finally reached trial in 2015, an unexpected form of evidence played an important role.
A tiny clump of moss discovered with the reburied remains helped investigators reconstruct what had happened. Researchers now describe the full scientific details of this investigation in a study published in the journal Forensic Sciences Research, explaining how the plant evidence helped confirm that a crime had occurred.
Matt von Konrat, the study’s lead author and the head of the botany collections at Chicago’s Field Museum, admits he enjoys detective television shows (the paper is named after the BBC’s Silent Witness). Still, he never expected his work with moss to become part of a criminal investigation.
FBI Turns to Botanists to Identify Moss Evidence
“One day in 2009, I answered the phone, and it was the FBI, asking if I could help them identify some plants,” says von Konrat. Agents later arrived at the Field Museum with a small moss sample that had been discovered about eight inches underground alongside reburied human remains at the cemetery.
“The investigators wanted to know what kind of moss it was and how long it had been buried in the soil,” says von Konrat.
To begin their analysis, von Konrat and his colleagues studied the moss under a microscope and compared it with preserved specimens in the museum’s botanical collections. The team identified the plant as Fissidens taxifolius, commonly known as common pocket moss.
Moss Species Reveals the Original Grave Location
“We did a survey of the different kinds of mosses growing near the crime scene, and that species of moss was not growing there,” says von Konrat. “But when I surveyed the rest of the cemetery, we found a huge colony of that species of moss growing in the same area where the investigator suspected the bones had been dug up from. So that gave us pretty strong evidence that the remains had come from this other section of the cemetery.”
Investigators, however, needed more than the species identification. They also needed to know the age of the moss. The defendants argued that the remains might have been moved by someone else before they began working at the cemetery. Because the moss had been buried along with the relocated remains, estimating how long it had been underground could help establish when the bones were moved.
“Moss is a little bit freaky,” says von Konrat. “Mosses have an interesting physiology, where even if they’re dry and dead and preserved, they can still have an active metabolism, a few cells that are still active. The amount of metabolic activity deteriorates over time, and that can tell us how long ago a moss sample was collected.”
Chlorophyll Analysis Estimates Moss Age
Scientists can estimate plant metabolic activity by examining chlorophyll, the green pigment responsible for photosynthesis. As a plant ages and its cells stop functioning, chlorophyll gradually breaks down. The researchers measured how much light was absorbed by chlorophyll in moss samples whose ages were already known, including fresh material and specimens that had been stored in the museum collection for 14 years. They then performed the same analysis on the moss recovered from the cemetery.
The results strongly suggested that the evidence sample was only about one or two years old, strengthening the case against the cemetery workers. In 2015, the defendants were convicted of desecrating human remains.
Moss Evidence Helps Secure Convictions
“Every once in a while, a case comes along where the FBI has to call in experts to aid in the collection of evidence, do analyses, present the evidence to the prosecutors, and testify about their work if necessary to secure a conviction. The Burr Oak Cemetery case was one of those cases where we reached out to the Chicago Field Museum Botanical Program, which proved to be extremely invaluable because plant material inside the cemetery was key to charging four individuals and securing their convictions,” says Doug Seccombe, a former FBI agent who worked on the case and was a co-author on the new paper.
After the Burr Oak Cemetery investigation, von Konrat has been asked to assist with several additional cases involving moss. Even so, examples like this remain uncommon in forensic science. In 2025, he and several colleagues published another study examining the role of mosses and other bryophytes as forensic evidence. Their review found only a dozen or so documented cases during the past century.
“Mosses are often overlooked, and we hope that our research will help raise awareness that there are other plant groups out there, apart from flowering plants, and that these serve a very important role in society and around us,” says von Konrat. “But most importantly, we want to highlight this microscopic group of plants as a tool for law enforcement. If we can elevate mosses as potential evidence, maybe it could help some families somewhere in the future.”
Reference: “Silent witness: a moss provides important evidence in solving a cemetery crime” by Matt von Konrat, Llo Stark, Jenna Merkel, Anne Grauer, Wayne Jakalski, Paul Kiefer, Danny Kreider, Eric Leafblad, Alan Lichamer, Gary Merrill, Jason Moran, Gavin Quinn, Doug Seccombe, Kathryn Sodetz and Matthew Thrun, 5 March 2026, Forensic Sciences Research.
DOI: 10.1093/fsr/owaf038
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