Framed for Murder By His Own DNA
We leave traces of our genetic material everywhere, even on things we’ve never touched. That got Lukis Anderson charged with a brutal crime he didn’t commit.
▻https://www.themarshallproject.org/2018/04/19/framed-for-murder-by-his-own-dna
▻https://d1n0c1ufntxbvh.cloudfront.net/photo/08e9c6e6/31752/1140x
Back in the 1980s, when DNA forensic analysis was still in its infancy, crime labs needed a speck of bodily fluid—usually blood, semen, or spit—to generate a genetic profile.That changed in 1997, when Australian forensic scientist Roland van Oorschot stunned the criminal justice world with a nine-paragraph paper titled “DNA Fingerprints from Fingerprints.” It revealed that DNA could be detected not just from bodily fluids but from traces left by a touch. Investigators across the globe began scouring crime scenes for anything—a doorknob, a countertop, a knife handle—that a perpetrator may have tainted with incriminating “touch” DNA.But van Oorschot’s paper also contained a vital observation: Some people’s DNA appeared on things that they had never touched.In the years since, van Oorschot’s lab has been one of the few to investigate this phenomenon, dubbed “secondary transfer.” What they have learned is that, once it’s out in the world, DNA doesn’t always stay put.
Objects bearing DNA of a participant who never touched them
Objects bearing foreign DNA that didn’t match any participants