The problem with DNA vs. IGG ?

The FBI standards for DNA laboratories were last updated in 2011, and, to this day, no changes have been made to reflect the 2016 Indianapolis findings. There are currently no widespread standards in place that are specifically aimed at preventing cross-contamination with touch-transfer DNA in the laboratories where various evidentiary objects are examined. This means that when objects that are placed on shared surfaces in the laboratory, to be examined or photographed, for example, they are subjected to cross-contamination by touch-transfer DNA. The same goes for the initial discovery and investigation of the evidence when the evidence is first handled by police officers.

The presentation of touch-transfer DNA as bulletproof to a jury is thus even more worrisome. During a criminal trial, lawyers for the government and for the accused are expected to present competing possibilities of how a crime could have occurred, and who may have been responsible for the crime. A jury is not confined to mathematical computation of criminal culpability. Instead, a jury is free to choose among reasonable constructions of the evidence. Overcome with anxiety and fear of making the wrong choice, jurors tend to rely on the existence of, or the lack of, forensic or DNA evidence presented to them at trial. Thus, when prosecutors present to a jury touch-transfer DNA evidence with the same oomph as large-sample DNA evidence, the jurors, under the influence of pre-set expectations for scientific evidence to prove culpability and the common notion that DNA evidence is inherently trustworthy, feel compelled to convict. The result is touch-transfer DNA can readily lead to conviction of the innocent.

In 2007, Amanda Knox was charged with the murder of her roommate based a minuscule amount of touch-transfer DNA. Knox's DNA, and the DNA of the victim, were found on a kitchen knife that was located in the home of Knox's friend, who was charged as a co-conspirator in the murder. Since the victim was never in the co-conspirator's residence, the prosecution insisted that the only way for the victim's DNA could have found its way into that home and onto that knife, would have to be through direct contact—the murder. In 2009, an Italian jury convicted Knox, even though the knife in question did not match the entry wounds on the victim's body. It was not until 2015 that Ms. Knox was exonerated based on a more precise understanding of how DNA transferred through contact and on concerns with touch-transfer DNA cross-contamination.

In 2012, Lukis Anderson was arrested and charged with the murder of a millionaire in California. Traces of his DNA were found on the victim's fingernails. Law enforcement crafted a theory of the case based on this evidence and Anderson's lengthy criminal record, dangling the death penalty over Anderson's head. Anderson was unable to effectively assist in his own defense. "Maybe I did do it," he told his public defender, not remembering what happened on the night in question due to significant intoxication. After spending five months in jail, Anderson was released when it was uncovered that he was at the hospital when the crime occurred, recovering from intoxication. But how did his DNA get onto the victim's fingernails? Anderson was the victim of touch-transfer DNA misinformation. The two paramedics who had treated Anderson for intoxication, hours before the millionaire was murdered, later responded to the scene of the murder with Anderson's DNA already on them. Contact between the paramedics and the millionaire resulted in the exchange of DNA on their hands, which just happened to include Anderson's DNA from contact that took place hours prior.

In 2014, Oklahoma City police officer Daniel Holtzclaw was charged with various sexual assault crimes stemming from accusations of women he encountered while on patrol. While the case initially appeared brittle, from ever-changing victim accounts to evidence contradicting the stories altogether, a speck of DNA from one of the accusers was found on the officer's uniform pants. Unlike a visible sample of identifiable DNA (think Monica Lewinski's blue dress stain), the DNA found on Holtzclaw's pants was instead invisible, touch-transfer DNA. In fact, his patrol car's door handle produced four times as much DNA as the speck on his pants. The evidence also confirms that Officer Holtzclaw searched the accuser's purse for evidence on behalf of the police department, before he was swabbed for DNA, rummaging through her personal belongings, his hands plausibly coming into contact with a plethora of her DNA. He also used the restroom, touching his pants in the process. Consistent with touch-transfer DNA properties, an unaccounted-for and unknown male's DNA had also been found on Holtzclaw's pants together with the female's DNA. Nevertheless, the prosecutor told the jury that the speck of female DNA evidence was conclusive proof of sexual contact between Holtzclaw and the victim, and then, unsupported by his own evidence, claimed that the particular DNA came from the victim's vagina—a scientifically impossible conclusion. The jury found Holtzclaw guilty and sentenced him to 263 years in prison. His appeal is presently pending. Daniel Holtzclaw currently sits behind bars and maintains his innocence.