Framed for Murder By His Own DNA

This was crazy town!

Framed for Murder by His Own DNA, by Katie Worth via The Marshall Project.

In 2008, German detectives were on the trail of the "Phantom of Heilbronn." A serial killer and thief, the Phantom murdered immigrants and a cop, robbed a gemstone trader, and munched on a cookie while burglarizing a caravan. Police mobilized across borders, offered a large reward, and racked up more than 16,000 hours on the hunt. But they struggled to discern a pattern to the crimes, other than the DNA profile the Phantom left at 40 crime scenes in Germany, France, and Austria.

At long last, they found the Phantom: An elderly Polish worker in a factory that produced the swabs police used to collect DNA. She had somehow contaminated the swabs as she worked. Crime scene investigators had, in turn, contaminated dozens of crime scenes with her DNA.

Pierogies and serial killers, indeed.

There now exists a small pile of studies exploring how DNA moves: If a man shakes someone's hand and then uses the restroom, could their DNA wind up on his penis? (Yes.) If someone drags another person by the ankles, how often does their profile clearly show up? (40 percent of the time.) And, of utmost relevance to Lukis Anderson, how many of us walk around with traces of other people's DNA on our fingernails? (1 in 5.)

Whether someone's DNA moves from one place to another—and then is found there—depends on a handful of factors: quantity (two transferred cells are less likely to be detected than 2,000), vigor of contact (a limp handshake relays less DNA than a bone-crushing one), the nature of the surfaces involved (a tabletop's chemical content affects how much DNA it picks up), and elapsed time (we're more likely carrying DNA of someone we just hugged than someone we hugged hours ago, since foreign DNA tends to rub off over time). 

Then there's a person's shedding status: "Good" shedders lavish their DNA on their environment; "poor" shedders move through the world virtually undetectable, genetically speaking. In general, flaky, sweaty, or diseased skin is thought to shed more DNA than healthy, arid skin. Nail chewers, nose pickers, and habitual face touchers spread their DNA around, as do hands that haven't seen a bar of soap lately—discarded DNA can accumulate over time, and soap helps wash it away.

And some people simply seem to be naturally superior shedders. Mariya Goray, a forensic science researcher in van Oorschot's lab who coauthored the juice study with him, has found one of her colleagues to be an outrageously prodigious shedder. "He's amazing," she said, her voice tinged with admiration. "Maybe I'll do a study on him. And the study will just be called, 'James.'"

She hopes to develop a test to determine a person's shedder status, which could be deployed to assess a suspect's claims that their DNA arrived somewhere innocently.

Such a test could have been useful in the case of David Butler, an English cabdriver. In 2011, DNA found on the fingernails of a woman who had been murdered six years earlier was run through a database and matched Butler's. He swore he'd never met the woman. His defense attorney noted that he had a skin condition so severe that fellow cabbies had dubbed him "Flaky." Perhaps he had given a ride to the actual murderer that day, who inadvertently picked up Butler's DNA in the cab and later deposited it on the victim, they theorized.

Investigators didn't buy the explanation, but jurors did. Butler was acquitted after eight months in jail. Upon release, he excoriated police for their blind faith in the evidence.

"DNA has become the magic bullet for the police," Butler told the BBC. "They thought it was my DNA, ergo it must be me."

DNA seems like some sci fi shit in the first place, and thank goodness more has been learned about it. Obviously, DNA has helped resolve more crimes and convict more criminals than it has locked up innocent people. HOWEVER, it’s as though we all overcorrected and have maybe over-relied on DNA. The story of Lukis Anderson told in this TMP article deserves its own light and time. But even with a solid alibi for Anderson, the case continued to be prosecuted! Really fascinating and [spoiler] thank goodness it all worked out.