DNA evidence breaking tough cases open but there are problems

Juries often think DNA evidence is infallible, but that's not always the case. It all comes down to proper lab work.
Written by Richard Koman, Contributor

The role of DNA in criminal trials is getting a lot of attention in North Dakota, where DNA is crucial to two high-profile murder prosecutions. The Fargo Forum reports:

Last month, a jury found Alfonso Rodriguez Jr. guilty of kidnapping and murdering Dru Sjodin in part because of DNA analysis that concluded tiny traces of blood in Rodriguez’s car came from Sjodin.

Also last month, Moe Maurice Gibbs was charged with the murder of Mindy Morgenstern after a DNA sample he provided to authorities was matched to tissue found beneath the victim’s fingernails. After Gibbs’ arrest, Fargo police announced DNA evidence from a 2004 sexual assault also tied Gibbs to that crime.

Juries often think DNA evidence is infallible, but that's not always the case. It all comes down to proper lab work.

“As long as you have human beings working cases, mistakes can be made. But if the process is done the correct way, it’s a very reliable scientific method,” said Wahl, Thomas Wahl, who is helping to set up a state-of-the-art DNA laboratory on the campus of North Dakota State University.

“Our goal here is to try to implement cutting-edge technology and develop some niches so we can offer services to government crime laboratories as well as the defense community,” said Wahl, who came to North Dakota from Las Vegas along with Berch Henry, who will head NDSU’s new lab.

Reliance on DNA is creating crushing caseloads for police labs across the country. Wahl left his position in Las Vegas because he was “sick and tired of being sick and tired.” In Minnesota, turnaround time is two to three months, said Jim Iverson, a forensic science supervisor in St. Paul.

“We would love to have a 30-day turnaround. You do the best you can with what you have,” said Iverson, whose lab gets about 2,000 cases a year, many of them involving sexual assault.

Hastings, MN, public defender Christine Funk says the technology has gotten more and more precise but that doesn't mean lawyers or courts can take results as a given.

Cloudiness can creep in, she said, when a sample lifted from an object or person contains more than one DNA profile, when contamination of a sample occurs or when a given DNA profile is compared with profiles contained in a data bank.

With the latter, she said, a match doesn’t necessarily mean a culprit has been identified. Funk said that’s because the probability of connecting a particular DNA profile to one in a data base is much higher than it would be if a single profile is compared at random to another single profile.

William Thompson, a professor in the department of criminology, law and society at the University of California Irvine, says that DNA evidence is especially worrisome if it's the only evidence presented.
“There’s one chance in millions that any single person will win the lottery. But if you sell enough lottery tickets, somebody’s going to win,” he said, adding it is the same with a genetic lottery.

“Even though there might be one chance in millions or billions that a particular person would by chance lose by matching, if you have enough people in the data base somebody’s going to lose, even if they’re innocent,” he said.

U.S. Attorney Drew Wrigley, though, says DNA evidence is critical, not only for police to ID suspects but to pass the "reasonable doubt" standard of criminal trials.

“The reality is the science (of DNA) is beyond reproach. But you have to look at how it’s done and how it’s collected. To me, it ultimately answers that question of certainty for a juror. The standard is proof beyond a reasonable doubt. But I think there’s an important role for the certainty that comes with this type of evidence.”
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