A Strange New Way to Solve Crimes

Think of it as CSI: E. coli. New science is finding that each one of us brings with us (and can’t help but leave behind) a unique bacterial signature everywhere we go–a germy John Hancock. As you move through a scene and shed your microbes, the space starts to reflect your bacterial signature, potentially tying you to it and giving away a lot about you in the process.

To test how much bacteria gets left behind and what it can reveal about identity, scientists will compare the swabs collected from the robbers and see if they can differentiate them from those of the homeowners and their cat, whose paw the scientists also swabbed. They’ll also try to see if they can tease out the signatures from the samples from the scene. If they can, it will provide early proof that an outsider’s bacteria is distinct enough from the homeowners’ to confirm that a stranger was in the house.

If this holds true, and evidence suggests it might, it would mean crime scenes are riddled with valuable clues that are currently left untested. Crime experts agree that the field of forensics needs cheaper, faster ways to gather investigative leads like these. Trace evidence–the kind found through hairs, fibers or paint–typically requires chemical analysis, which can be expensive and inaccurate if there’s not enough of it to analyze. Thanks to advances in science, however, bacterial evidence can be sequenced affordably, quickly and with startling accuracy. That’s why forensics experts are saying it’s the leading contender for next-generation investigations.

Court challenges will follow the scientific ones–it took a decade for DNA to be a courtroom staple

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