Posted on 01/04/2017 4:19:31 AM PST by Kaslin
Have you 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, charged with rape or convicted of murder.
This year, I'll be using my syndicated column and new investigative show on CRTV.com to shed light on the use and abuse of touch DNA in the criminal justice system. Detection methods involving tinier and tinier DNA samples have advanced rapidly during the last three decades.
But the mere presence of DNA does not prove a crime happened. It does not tell you how or when the material got to its discovered location. Contrary to Hollywood crime show oversimplifications, DNA is not a synonym for "guilty."
You may be familiar with a few high-profile cases where touch DNA led investigators astray. Trace amounts of DNA on a knife and bra clasp in 2007 were key to American student Amanda Knox's prosecution and conviction on charges of murdering her roommate in Italy. But when American forensic expert Dr. Greg Hampikian and others exposed contamination, interpretation and replicability/reliability problems with the DNA evidence, the Italian Supreme Court threw out the convictions 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, nearly comatose and under 24/7 medical supervision the night the crime occurred in 2012. As Scientific American reported, the defendant's DNA had been transferred inadvertently by paramedics who had touched and treated him three hours before arriving at the businessman's home. The EMTs used the same oxygen monitor on both men's fingers, unknowingly transferring skin cell DNA from the homeless man to the multimillionaire he had never met.
The case provided a definitive example of "a DNA transfer implicating an innocent person," the journal noted, and illustrated "a growing opinion that the criminal justice system's reliance on DNA evidence, often treated as infallible, actually carries significant risks."
Secondary transfer and contamination problems with touch DNA were most famously revealed by the "Phantom of Heilbronn," a case involving skin cell DNA from a "mystery" female serial killer and thief in Germany -- which police years later acknowledged most likely belonged to a lab or factory worker who had handled cotton swabs used by investigators across Europe.
Touch DNA is also central to the murder case of Colorado toddler JonBenet Ramsey. Thanks to joint reporting by Denver's 9News and the Boulder Daily Camera, current Boulder County district attorney Stan Garnett announced three weeks ago that he is reopening the DNA portion of the investigation initially conducted by his predecessor, Mary Lacy. In 2008, she concluded in a letter exonerating the Ramsey family that an unknown male's DNA on JonBenet's underwear must belong to the killer because no innocent explanation existed for its presence.
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 case of former Oklahoma City police officer Daniel Holtzclaw, who was sentenced to 263 years in prison for alleged sexual assaults, I've encountered firsthand an alarming ignorance of the pitfalls and limitations of DNA evidence. That ignorance has been compounded by the stubborn unwillingness of ill-informed police detectives and prosecutors to acknowledge their scientific shortcomings. As a racially charged mob of Black Lives Matter activists demanded social justice and threatened riots in the volatile summer of 2014 (the summer of Ferguson), Holtzclaw was charged, tried and convicted despite a mountain of reasonable doubt.
During my two-hour interview with lead detectives Rocky Gregory (now a homicide detective) and Kim Davis (now retired and hailed as a social justice champion) of the Oklahoma City police department, both adamantly insisted that transfer DNA "never happens." Davis said it was "hard to get." Gregory claimed it was "very rare" and "almost impossible." Prosecutor Gayland Gieger similarly mocked the touch DNA phenomenon at trial and possibly misled the jury about the DNA sourcing.
As Erica Fuchs, a microbiologist and molecular biologist with a lab research specialty in DNA who supports Daniel Holtzclaw and has made crucial discoveries involving the DNA evidence that no one else had realized at trial, 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 (and everywhere else) their assumptions and actions."
Yet another reason not to shake hands. We should switch to the Vulcan greeting.
Now this is not only an interesting but an important article. Thanks for sharing.
Or wear gloves
Good for Michelle Malkin for writing abut this silly “science.” I think people would be shocked at how many places their DNA may innocently appear.
I’m always worried about the back of stamps and envelopes. Now that they have self stick ones, my DNA as well as my fingerprints are in peril.
Add to this possible accuracy and honesty problems in some forensic labs, and our justice system becomes suspect.
“Add to this possible accuracy and honesty problems in some forensic labs, and our justice system becomes suspect.”
Recall that during the Duke lacrosse case, the entire lacrosse team was tested for DNA contact with the accuser, and cleared, before anyone was even charged.
IE, the absence of any DNA from any team member, proved no one had any contact with her.
But so what? The prosecutor, Nifong —who had just been saying that DNA was “bulletproof” and would immediately clear the innocent — did a 180 and then asked,”how does DNA exonerate you?” and said he would try the case “the old-fashioned way, before DNA”.
Absence of DNA —especially in a case where three people allegedly struggled with a woman in a tiny confined space for a half hour, with fighting, biting, kicking, etc., and the woman raped in every possible way by all three (including being hoisted in mid-air), and while two of the accused were miles away at the time —
does prove innocence.
Unless the prosecutor (and the media) insist you must be guilty anyway...
Add to this possible accuracy and honesty problems in some forensic labs, and our justice system becomes suspect.
*****************
The FBI’s multi-decade long claims regarding matching hair to individuals comes immediately to mind.
I hate the feel of gloves. I only wear them when I have to, for hard work or cold weather.
Looks like humans are too stupid to know how to use the tools that they create.
They put too much credence in them. They think that their tools can never be wrong.
Prosecutors are only too happy to be able to convict someone, anyone, so they can declare the case “closed.”
Is there any kind of forensic detection technique that hasn’t been described as “infallible?”
Like any human identification technology Touch DNA can be useful but can also be abused. Touch DNA or trace DNA can be found on the victim’s clothing, a partial fingerprint, skin cells inside a rubber glove left by a suspect, or anything a suspect may have come in contact with. In cases where there is no real physical evidence touch DNA can be used to flag who was present at the scene who was not expected to be there. That person of interest can then be interviewed or investigated to find additional evidence. Due to the ability of DNA to be transferred by casual contact there is potential for this technology to be abused. A person shouldn’t be convicted if a single trace sample of his DNA was found at a crime scene, but if you find multiple samples from someone who had no business being there it carries more weight.
The blue nitrile gloves are easy to use for most anything. I keep a box in the garage and use them when changing the oil or taking dead mice out of traps.
Sounds good. I’m going to get them for my basement, attack and backyard work.
Gloves to come back in style hey look classy any way.
Indeed, since Leonard Nemoy reported that it is actually a variation on a Hebraic priestly blessing. Ever since I learned that, I like it even better.
Actually, the issue of cross-contamination has always been a problem in DNA testing. I remember reading that PCR techniques are so sensitive that they can pick up the DNA of the police officer who handled the samples. It is essential to handle all samples with gloved hands, because they *will* become contaminated if touched with bare hands.
Furthermore, it is not necessary for direct contact to occur for a sample to be contaminated with extraneous DNA. Opening a small test tube containing a DNA suspension can cause an invisible spray of DNA that would contaminate objects nearby—leading to false positives in other samples.
In the real world (where I work), the issue of DNA contamination is so prevalent that there are special tools and techniques designed specifically to decrease—but never eliminate—cross-contamination.
The certainty of the prosecutors mentioned in the articles does not come from the scientists who developed molecular biology techniques. It exists because the prosecutors do not fully understand the techniques or the sources of contamination and have no experience actually preparing and analyzing samples. If they were to spend six months or so in a real molecular biology lab, spending as much time learning how to minimize contamination as they spend learning the techniques, they would lose those illusions that cross-contamination is nearly impossible.
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