ShareThis Page

Forensic nightmare: 'Touch DNA'

| Sunday, Jan. 8, 2017, 9:00 p.m.

Heard of “touch DNA?” This mundane yet menacing phenomenon exposes the double-edged sword of forensic science. With just an innocent handshake, an indirect transfer of epithelial cells, you could find yourself suspected of heinous crimes.

This year, I'll be using my syndicated column and new investigative show on to shed light on touch DNA's use and abuse in the criminal justice system. Detection methods involving tinier and tinier DNA samples have advanced rapidly. But DNA's mere presence does not prove a crime happened or tell how or when the material got to its discovered location.

Contrary to Hollywood, DNA is not a synonym for “guilty.”

In a few high-profile cases, touch DNA led investigators astray. Trace amounts of DNA in 2007 were key to American student Amanda Knox's murder conviction in Italy. But when an American forensic expert and others exposed problems with the DNA evidence, the Italian Supreme Court threw out her conviction eight years after the killing.

At the annual American Academy of Forensic Sciences conference last February, experts spotlighted the case of a homeless man charged with murdering a Silicon Valley mogul at his mansion — despite the accused being hospitalized and nearly comatose the night the crime occurred in 2012. As Scientific American reported, the defendant's DNA had been transferred inadvertently by paramedics who had treated him three hours before arriving at the businessman's home. They used the same oxygen monitor on both men's fingers. The case is a definitive example of “a DNA transfer implicating an innocent person,” the journal noted.

Thanks to joint reporting by Denver's 9News and the Boulder Daily Camera, the Boulder County district attorney is reopening the DNA portion of the JonBenet Ramsey murder investigation. Exonerating the Ramsey family in 2008, his predecessor concluded that an unknown male's DNA on JonBenet's underwear must be the killer's because no innocent explanation existed for it. A growing body of peer-reviewed scientific literature says otherwise. Unfortunately, many state crime labs and police departments haven't caught up.

In my own investigation of the sexual-assaults case of former Oklahoma City policeman Daniel Holtzclaw, who was sentenced to 263 years in prison, I've encountered alarming ignorance of DNA evidence's pitfalls and limitations, compounded by the stubborn unwillingness of ill-informed detectives and prosecutors to acknowledge their scientific shortcomings. In 2014, Holtzclaw was convicted despite a mountain of reasonable doubt.

As Erica Fuchs, a micro- and molecular biologist with a lab research specialty in DNA who supports Holtzclaw and has made crucial discoveries involving the DNA evidence, told me: “When people invest themselves in a belief, it can be easier to ignore evidence that conflicts or challenges that belief. Admitting that non-intimate skin cell DNA transfer is a reasonable explanation for the DNA evidence in Daniel's case may make a lot of people in the media question their assumptions and actions.”

Michelle Malkin is host of “Michelle Malkin Investigates” on

TribLIVE commenting policy

You are solely responsible for your comments and by using you agree to our Terms of Service.

We moderate comments. Our goal is to provide substantive commentary for a general readership. By screening submissions, we provide a space where readers can share intelligent and informed commentary that enhances the quality of our news and information.

While most comments will be posted if they are on-topic and not abusive, moderating decisions are subjective. We will make them as carefully and consistently as we can. Because of the volume of reader comments, we cannot review individual moderation decisions with readers.

We value thoughtful comments representing a range of views that make their point quickly and politely. We make an effort to protect discussions from repeated comments either by the same reader or different readers

We follow the same standards for taste as the daily newspaper. A few things we won't tolerate: personal attacks, obscenity, vulgarity, profanity (including expletives and letters followed by dashes), commercial promotion, impersonations, incoherence, proselytizing and SHOUTING. Don't include URLs to Web sites.

We do not edit comments. They are either approved or deleted. We reserve the right to edit a comment that is quoted or excerpted in an article. In this case, we may fix spelling and punctuation.

We welcome strong opinions and criticism of our work, but we don't want comments to become bogged down with discussions of our policies and we will moderate accordingly.

We appreciate it when readers and people quoted in articles or blog posts point out errors of fact or emphasis and will investigate all assertions. But these suggestions should be sent via e-mail. To avoid distracting other readers, we won't publish comments that suggest a correction. Instead, corrections will be made in a blog post or in an article.