In 2009, investigators at Burr Oak Cemetery in Alsip, Illinois, discovered that employees had been digging up old graves, relocating the remains, and reselling the emptied plots. The defendants denied the timeline. The evidence that broke the case was a clump of moss.
The moss — Fissidens taxifolius, common pocket moss — was found with the reburied remains. Von Konrat, a Field Museum botanist, identified the species, then did something simple: he measured how much light its chlorophyll absorbed. Moss physiology is unusual. Even dried and buried, some cells retain metabolic activity. The chlorophyll degrades at a measurable rate. Fresh moss absorbs strongly. Museum specimens preserved for fourteen years absorb barely at all. The evidence moss fell at the young end — a year or two old, consistent with recent disturbance.
The species told him where: Fissidens taxifolius grew abundantly at the suspected original gravesite but not at the reburial location. The chlorophyll told him when. Species plus degradation rate gave the prosecution both halves of the question — origin and timeline — from a single clump of plant tissue.
The moss did not witness anything. It could not testify. But its chemistry carried a record no one had asked it to keep. The chlorophyll was simply fading, as chlorophyll does, and the rate of fading was a clock that ran whether or not anyone was reading it.
The through-claim: degradation is measurement. A process running down is also a process recording how long it has been running. The moss was not evidence because someone preserved it — it was evidence because no one could stop it from decaying, and the decay had a rate.