Lukis Anderson couldn’t remember any murder.
“Nah, nah, nah. I don’t do things like that,” he told his public defender when the DNA results came back. “But maybe I did.”
Anderson, a 26-year-old, homeless alcoholic who suffered blackout spells, was charged in December 2012 with the murder of Raveesh Kumra, a wealthy, 66-year-old investor from Monte Sereno, California. The only evidence against Anderson was his DNA – found on trimmings of Kumra’s fingernails.
DNA is the gold standard of forensic evidence. So Kelley Kulick, Anderson’s defender, began composing arguments for a lenient sentence in a case that could carry the death penalty. She obtained medical and mental health records, hoping to portray Anderson as a sympathetic figure: homeless even in childhood, an alcoholic with memory problems dating to a drunken accident where he was hit by a truck.
Kulick found more than grounds for leniency in Anderson’s medical records: She found proof of innocence. On the evening of Kumra’s murder, Anderson drank himself into unconsciousness and spent the night in the hospital.
Surely, DNA was foolproof. Could the man in the hospital have been misidentified? No. One of the medics who transported Anderson to the hospital said he’d picked up the guy so many times that he knew his birthdate by heart. So how did Anderson’s DNA wind up on Kumra’s fingernails?
More than a century ago, French criminologist Edmond Locard proposed that “every contact leaves a trace.” The concept means that everywhere we go, we take something with us and leave something behind. “Locard’s Principle” is the foundation of modern criminalistics.
Criminals who leave traces of their DNA at crime scenes are likely to be caught. When traces of DNA left in one place migrate to another, an innocent person like Anderson can become a suspect.
I’m grateful to a reader of last month’s column about the “Woman Without a Face” and the possibility of DNA contamination of evidence. He sent me a report on the Anderson case written by Katie Worth of PBS/Frontline.
DNA is the best tool we have, but techniques have become far too sensitive. Scientists can isolate and sequence the amount of DNA present in just a few cells, and cells do migrate. DNA can be detected from traces left by a touch, and it can turn up in places that were never touched.
In one experiment, volunteers sat around a table, chatting and sharing a pitcher of juice. They didn’t touch each other; they didn’t touch each other’s glasses. But a third of the glasses and a third of the volunteers’ hands yielded the DNA of one or more of the other participants.
Half the chairs and glasses, all the volunteers’ hands and the table had identifiable DNA that didn’t belong to any of the participants. Perhaps this foreign DNA came from “the lover they kissed that morning, the stranger with whom they had shared a bus grip or the barista who handed them their afternoon latte.”
Every day, we shed skin cells by the millions. Human DNA is present on 92 percent of escalator rails, restroom door handles, shopping baskets and coins.
Lukis Anderson never met Raveesh Kumra, was never in his presence. The only link investigators could find was that the medics who brought Anderson to the hospital were then dispatched to Kumra’s murder scene where they examined and touched the body.
Anderson’s is the only known case where “touch” DNA implicated an innocent man. It won’t be the last.
Dr. Carol J. Huser, a forensic pathologist, served as La Plata County coroner from 2003-12. She now lives in Florida and Maryland. Reach her at firstname.lastname@example.org.