Moss Evidence Helped Convict Illinois Grave Robbers in Landmark Case

A seemingly insignificant clump of moss played a pivotal role in securing convictions in a notorious grave-robbing scandal that rocked Burr Oak Cemetery in Alsip, Illinois. Nearly two decades after the initial discovery of desecrated burial plots, scientists have detailed how forensic botany helped bring the perpetrators to justice.

The Crime at Burr Oak Cemetery

In 2009, an investigation revealed that four cemetery workers had exhumed over 100 bodies, relocating the remains to resell burial plots for financial gain. The scandal drew national attention, particularly due to the cemetery being the final resting place of prominent African Americans, including Emmett Till, whose 1955 murder was a catalyst for the civil rights movement, and blues singer Dinah Washington.

The Role of Forensic Botany

The FBI turned to Dr. Matt von Konrat, head of botanical collections at the Field Museum in Chicago, for assistance. “They asked if I knew about moss and brought the evidence to the museum,” von Konrat stated according to reporting from The Guardian.

Forensic specialists had discovered a piece of moss, approximately the size of a fingertip, alongside the reburied remains. Von Konrat was tasked with identifying the moss species and determining how long it had been disturbed.

Identifying the Moss and Determining Time Since Disturbance

After microscopic examination and comparison with specimens in the Field Museum’s collection, the moss was identified as common pocket moss, scientifically known as Fissidens taxifolius. A survey of the cemetery revealed that this species did not grow in the area where the bodies were found, but was abundant in a lightly shaded area beneath trees – the suspected original burial location. This indicated the moss had been moved with the bodies.

Crucially, scientists leveraged a unique characteristic of moss to estimate the time since the disturbance. “When we’re dead, we’re dead, but with mosses, it’s bizarre. Even when we might think they’re dead, they can still have an active metabolism,” explained von Konrat in The Guardian. By measuring the moss’s chlorophyll absorption and re-emission of light, researchers determined the moss had been buried for less than 12 months.

Securing the Convictions

This finding was critical because the defendants argued the crimes occurred before their employment at the cemetery, claiming the events took place years earlier. “We concluded that the moss had been buried for less than 12 months and that was vital because the accused’s whole line of defence was that the crime took place before their employment,” von Konrat said . Doug Seccombe, a former FBI agent involved in the case and co-author of the study published in Forensic Sciences Research, confirmed that the plant material was “key” to securing the convictions.

The Future of Forensic Botany

Von Konrat, a fan of forensic science dramas, expressed surprise at the application of his expertise in a criminal case. He hopes this case will highlight the potential of mosses and other plant life in forensic investigations. “I had no idea we’d be using our science, our collections, in this manner,” he said . “It underscores how important natural history collections are. We never know how we might apply them in the future.”