In a development reminiscent of dramatic courtroom television, Federal Bureau of Investigation agents and scientific experts leveraged a diminutive cluster of moss to aid in the prosecution of four cemetery employees implicated in their disturbing grave-robbing activities.
The illicit operations at Burr Oak Cemetery, situated on the outskirts of Chicago, Illinois, came to light in 2009 when law enforcement initiated an inquiry, alleging that the workers had been exhuming existing burials, relocating the remains to other sections of the cemetery, and subsequently remarketing the interment spaces.
Following a thorough forensic examination, prosecuting attorneys contended that the remains of at least 29 individuals, amounting to approximately 1,500 bones, had been unlawfully removed and reinterred in an disused area within the cemetery’s expansive 150-acre property.
A comprehensive scientific exposition detailing the intricacies of this case has now been published, finally illuminating how an inconspicuous piece of moss proved instrumental in unraveling this nefarious scheme.
“One day in 2009, a call arrived from the FBI, inquiring about my capacity to assist in plant identification,” relates Matt von Konrat, the lead author of the study and chief botanist at Chicago’s Field Museum.
The FBI presented von Konrat with a fragment of moss recovered from a depth of eight inches beneath the soil’s surface, discovered in proximity to human remains that were suspected of having been exhumed and reburied.
Von Konrat and his team of collaborators successfully identified the specimen as common pocket moss (Fissidens taxifolius). Crucially, this particular species was not found growing at the location where the bones were unearthed. However, a substantial colony of the same moss was located elsewhere on the cemetery grounds – specifically, in the zone from which investigators presumed the remains had been extracted.
This crucial discovery established a tangible connection between the two primary sites of disturbance. However, as any aficionado of criminal investigations knows, establishing a definitive timeline is paramount, particularly to counteract the defendants’ common defense strategy, which typically asserts that the alleged grave-robbing activities predated their employment.
Fortuitously for the pursuit of justice, moss exhibits a characteristic analogous to radioactive decay, possessing a form of temporal degradation.
“Moss possesses a rather peculiar physiology,” observes von Konrat. “Even when desiccated and dormant, certain cells within moss can retain metabolic activity. The degree of metabolic functioning diminishes over time, which provides vital clues regarding the elapsed period since the moss sample was collected.”
To reconstruct the temporal sequence of events, the researchers meticulously analyzed the moss’s chlorophyll content. Chlorophyll, the pigment responsible for photosynthesis, degrades as moss decomposes.
The researchers quantified the light absorption capabilities of moss samples of established ages. By comparing these known degradation rates with the chlorophyll levels in the crime scene moss, they were able to accurately estimate the age of the botanical evidence.
Analyses indicated that the moss sample was merely one to two years old, strongly suggesting its disturbance occurred during the tenure of the accused cemetery employees, thereby invalidating their alibis. Consequently, in 2015, the cemetery staff were found guilty of desecrating human remains.
While the FBI’s engagement of subject matter experts to bolster convictions is a standard practice, the prominent role of moss as a key piece of evidence is a rarity. In 2025, von Konrat and his colleagues undertook an extensive review of historical criminal case files to ascertain the frequency with which mosses or analogous plant life had contributed to the resolution of other criminal enigmas.
Their investigation revealed that bryophytes, or moss-family plants, had featured as evidentiary support in only a limited number of cases—approximately a dozen—over the preceding century. Nevertheless, the current case underscores the considerable, albeit often overlooked, evidentiary potential of moss.
“We aspire that this case will foster a heightened appreciation for bryophytes and similar micro-flora in forensic investigations, thereby ensuring that critical botanical evidence is not inadvertently disregarded moving forward,” the researchers concluded.
It remains to be seen whether this precedent will serve as a foundational case for future criminal investigations or simply inspire a fictionalized legal drama, such as, perhaps, Law & Order: Forensic Botanicals Unit.
This research has been published in Forensic Sciences Research.
