How Moss Exposed a Grave Robbing Scheme at Burr Oak Cemetery

Nearly two decades after a scandal broke at Burr Oak cemetery in Alsip, Illinois, scientists have revealed details of how a seemingly insignificant clump of moss became crucial forensic evidence in convicting those responsible for a disturbing crime: the exhumation and resale of burial plots.

The Crime at Burr Oak Cemetery

Four cemetery workers dug up over 100 bodies and moved them to other parts of the grounds to resell the burial plots for profit. The scheme involved reburying remains just inches below the surface. Burr Oak Cemetery holds significant historical importance, serving as the final resting place for prominent African Americans, including Emmett Till, whose 1955 murder galvanized the civil rights movement, and blues singer Dinah Washington.

The Role of Forensic Botany

In 2009, the FBI contacted Dr. Matt von Konrat, head of botanical collections at the Field Museum in Chicago, seeking assistance with the investigation. Investigators had discovered vegetation, including a fragment of moss approximately the size of a fingertip, among the reburied remains. The task was to determine the moss’s origin and how long it had been disturbed.

Identifying the Moss Species

Microscopic analysis identified the moss as Fissidens taxifolius, commonly known as common pocket moss [Popular Science]. Further investigation revealed that this particular moss species did not grow at the reburial sites but was prevalent in a shaded area of the cemetery under trees – an area investigators believed was where the bodies were originally excavated.

Analyzing Moss Metabolism to Determine Timeframe

A key element in proving the perpetrators’ guilt was the unique metabolic properties of bryophytes (mosses). When detached from their environment, their metabolism slowly declines. Scientists examined chlorophyll activity by measuring light absorption and emission, comparing fresh samples from the cemetery with those in the museum’s collections. The analysis determined that the moss had been buried for less than 12 months before the evidence was collected, directly contradicting the defense’s claim that the crime could have occurred years earlier [The Guardian].

The Significance of the Evidence

“The plant material was key evidence in the lawsuit,” stated Doug Seccombe, a former FBI agent involved in the case [Field Museum]. Dr. Von Konrat emphasized the potential for botanical evidence in future forensic investigations, noting that “We never know when our knowledge will be used.”

Moss as a Forensic Tool

This case highlights the growing recognition of botany’s role in forensics. Even when seemingly lifeless, mosses retain a measurable metabolic activity that can provide crucial timelines in criminal investigations. The Burr Oak Cemetery case demonstrates how even the smallest piece of plant life can hold significant clues.