Matthew T. Mangino
GateHouse Media
October 26, 2018
The criminal justice system has embraced the nearly
unchallenged power of DNA evidence. The connection of a suspect to a victim or
crime scene by DNA evidence is considered the gold standard among criminal
investigators.
In a stunning bit of irony, as DNA analysis has improved and
the access to potential samples increased exponentially, DNA has opened the
door to wrongful arrests and convictions.
The emerging concern, long considered a theoretical risk but
only now confirmed by a variety of studies, is that the presence of DNA does
not prove that a suspect actually visited the scene or directly touched the
object in question. DNA can be transferred by other means.
DNA analysis once required substantial samples of blood or
other bodily fluids in order to create a DNA profile. However, technological
advances in the study of DNA now make it possible to produce a complete genetic
profile of a suspect from just a few cells found on a victim or object.
Attorney Erin E. Murphy, author of “Inside the Cell: The
Dark Side of Forensic DNA” said, “When you consider that over 10,000 cells can
fit on the head of a pin, it becomes clear that the days of testing only large,
visible stains are long past.”
According to Christopher Zoukis in Criminal Legal News,
scientists learned as early as 1997 that in addition to primary or direct
transfer — DNA transferred from an individual to an object — DNA can also be
transferred from the touched object to a second person. This phenomenon, known
as secondary DNA transfer, should have thrown up an immediate red flag in the
world of forensic DNA analysis — it did not.
Twenty-one years later — with DNA analysis evolving rapidly
— there has been an alarming lack of analysis of secondary transfer by forensic
scientists. Cynthia Cale of the Human Biology Program at the University of
Indiana published a 2016 study in the Journal of Forensic Science in which she
and her colleagues confirmed the secondary DNA transfer phenomenon.
The study concluded that secondary transfer of DNA through
intermediary contact is far more common than previously thought, a finding that
could have serious implications for the criminal justice system.
Cale’s experiment included people exchanging long handshakes
immediately prior to handling knives. When each knife was tested, the DNA of
the person who handled it was found in almost every case. However, 85 percent
of the time the tests found the DNA profile of a person who never touched the
knife. Perhaps even more shocking was that 20 percent of the time, the
non-touching person came back as the primary and in some cases, the only
contributor of DNA.
The problem is simple. The science has outpaced common
sense. DNA is not a magic bullet. The mere fact that it exists does not mean a
conviction is inevitable. DNA must be analyzed and carefully considered along
with all the other evidence in a case.
For instance, if a suspect’s DNA is found at a crime scene
and it was later learned that he was in jail when the crime was committed that
is pretty good proof that his DNA somehow ended up at the crime scene, even
though he never did. On the other hand, if a suspect with a DNA connection
tells police he was watching television with his girlfriend when the crime was
committed will he be given the same deference?
How far will police go to determine if the DNA was
transferred to the crime scene by some person, or some object, other than the
suspect him or herself?
DNA has helped exonerate individuals wrongfully convicted,
at times after long prison stays. DNA has long been lauded for solving “cold
cases,” investigations that have long remained dormant. Most importantly, DNA
has helped convicted offenders who may have otherwise evaded prosecution.
It would be unfortunate if advances in DNA technology would
be responsible for placing innocent people in jeopardy because trace evidence
was used to falsely place those people at a crime scene.
Matthew T. Mangino is of counsel with Luxenberg, Garbett,
Kelly & George P.C. His book The Executioner’s Toll, 2010 was released by
McFarland Publishing. You can reach him at www.mattmangino.com and follow him
on Twitter @MatthewTMangino.
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