STORY: "When DNA Implicates the Innocent," by Peter Andrey Smith, published by Scientific American on June 1, 2106.
SUB-HEADING: "The criminal justice system’s reliance on DNA evidence, often treated as infallible, carries significant risks"
GIST: "In
December 2012 a homeless man named Lukis Anderson was charged with the
murder of Raveesh Kumra, a Silicon Valley multimillionaire, based on DNA
evidence. The charge carried a possible death sentence. But Anderson
was not guilty. He had a rock-solid alibi: drunk and nearly comatose,
Anderson had been hospitalized—and under constant medical
supervision—the night of the murder in November. Later his legal team
learned his DNA made its way to the crime scene by way of the paramedics
who had arrived at Kumra's residence. They had treated Anderson earlier
on the same day—inadvertently “planting” the evidence at the crime
scene more than three hours later. The case, presented in February at
the annual American Academy of Forensic Sciences meeting in Las Vegas,
provides one of the few definitive examples of a DNA transfer
implicating an innocent person and illustrates a growing opinion that
the criminal justice system's reliance on DNA evidence, often treated as
infallible, actually carries significant risks. As virtually every field in forensics has come under increased
scientific scrutiny in recent years, especially those relying on
comparisons such as bite-mark and microscopic hair analysis, the power
of DNA evidence has grown—and for good reason. DNA analysis is more
definitive and less subjective than other forensic techniques because it
is predicated on statistical models. By examining specific regions, or
loci, on the human genome, analysts can determine the likelihood that a
given piece of evidence does or does not match a known genetic profile,
from a victim, suspect or alleged perpetrator; moreover, analysts can
predict how powerful or probative the match is by checking a pattern's
frequency against population databases. Since the mid-1990s the
Innocence Project, a nonprofit legal organization based in New York
City, has analyzed or reanalyzed available DNA to examine convictions,
winning nearly 200 exonerations and spurring calls for reform of the
criminal justice system. Like any piece of evidence, however, DNA is just one part of a larger
picture. “We're desperately hoping that DNA will come in to save the
day, but it's still fitting into a flawed system,” says Erin E. Murphy, a
professor of law at New York University and author of the 2015 book
Inside the Cell: The Dark Side of Forensic DNA.
“If you don't bring in the appropriate amount of skepticism and
restraint in using the method, there are going to be miscarriages of
justice.” For example, biological samples can degrade or be
contaminated; judges and juries can misinterpret statistical
probabilities. And as the Anderson case brought to light, skin cells can
move. Since 1997, when researchers first showed that it was possible to
gather genetic information about a person based on skin cells they had
left on an object, this type of trace evidence, also known as touch DNA,
has been increasingly collected from surfaces such as door and gun
handles. (In some jurisdictions, such as Harris County, Texas, the
number of touch DNA cases submitted for laboratory analysis increased
more than threefold between 2009 and 2013, often as a means of
identifying possible perpetrators for burglaries and thefts.) Commercial
companies now sell kits to law-enforcement agencies that can generate a
full genetic profile of an individual from as few as three to five
cells. Independent labs and scientists working on such projects as
identifying long-deceased individuals also employ the kits. Until recently, this type of DNA has been regarded as
incontrovertible proof of direct contact. But a growing number of
studies show that DNA does not always stay put. For example, a person
who merely carried a cloth that had been wiped across someone else's
neck could then transfer that person's DNA onto an object he or she
never touched, according to a study published earlier this year in the
International Journal of Legal Medicine. Similarly, Cynthia M. Cale, a master's candidate in human biology at the University of Indianapolis, recently reported in the
Journal of Forensic Sciences
that a person who uses a steak knife after shaking hands with another
person transfers that person's DNA onto the handle. In fact, in a fifth
of the samples she collected, the person identified as the main
contributor of DNA never touched the knife. Cale and her colleagues are
among several groups now working to establish how easily and how quickly
cells can be transferred—and how long they persist. “What we get is
what we get,” Cale says, “but it's how that profile is used and
presented that we need to be cautious about.” At the forensics meeting in Las Vegas, Kelley Kulick, a public
defender for the County of Santa Clara, presented the idea that
Anderson's DNA hitched a ride on the medics' uniforms. Just how often
transferred DNA ends in a wrongful accusation is unknown. “Although
clear cases appear to be quite uncommon, I think it's probably more
prevalent than we think,” says Jennifer Friedman, a public defender in
Los Angeles and DNA specialist. “The problem is that what we don't see
frequently is the ability to definitely prove that transfer occurred.” The erroneous interpretation of touch DNA for Anderson has now also
become a contentious issue for two co-defendants on trial for the Kumra
murder, Kulick says. No doubt DNA evidence remains an invaluable
investigative tool, but forensic scientists and legal scholars alike
emphasize that additional corroborating facts should be required to
determine guilt or innocence. Like all forms of evidence, DNA is only
one circumstantial clue. As such, Anderson's case serves as a warning
that a handful of wayward skin cells should not come to mean too much."
The entire story can be found at:
http://www.scientificamerican.com/article/when-dna-implicates-the-innocent/
See also related by post by forensic blogger Mike Bowers Forensics in Focus:( CSI DDS): at the link below; "With the FBI making a step to reel in its history of wayward forensic
conclusions, Scientific American wades into the “restructuring” of DNA
opinions in much the same way. The Fibbies had ample time and warning to
rethink and retool their poorly validated use of human hair morphology
when DNA profiling began to contradict hair IDs in earnest during the
1990’s. Better late than never, I guess. Now, in a stroke of irony, DNA is being seen in the media and some
scientific forensic circles as subject to similar human foibles. Its all about the DNA from “touch.” The Santa Barbara’s District Attorneys Office put
UCSB soccer star Eric Frimpong into
prison (and after release deportation back to Ghana) in 2008 from a
touch contact between a female student and his genitals. She was covered
in seminal fluids from her unindicted “boyfriend.” 2 bitemark dentists
showed up to finish the deal against him. These are same two DA
bitemark experts in
Bill Richards case from 1997 who recanted their testimony from that case in 2009. As you will read below, “touch” research is just starting after 20
years of DNA courtroom opinions in the US. In another irony, the testing
of DNA “walking” into a crime scene and by direct inference, a sexual
assault case, is reported from a forensic science graduate student. Odd?
Not really as this is forensics."
https://csidds.com/2016/06/07/the-bloom-is-off-forensic-dnas-infallibility-scientific-american/
PUBLISHER'S NOTE:
I have added a search box for content in this blog which now encompasses
several thousand posts. The search box is located near the bottom of
the screen just above the list of links. I am confident that this
powerful search tool provided by "Blogger" will help our readers and
myself get more out of the site.
The
Toronto Star, my previous employer for more than twenty
incredible years, has put considerable effort into exposing the
harm caused by Dr. Charles Smith and his protectors - and into
pushing for reform of Ontario's forensic pediatric pathology
system. The Star has a "topic" section which focuses on recent
stories related to Dr. Charles Smith. It can be found at:
http://www.thestar.com/topic/charlessmith
Information on "The Charles Smith Blog Award"- and its nomination process - can be found at:
http://smithforensic.blogspot.com/2011/05/charles-smith-blog-award-nominations.html
Please
send any comments or information on other cases and issues of
interest to the readers of this blog to: hlevy15@gmail.com;
Harold Levy;
