DNA testing developing, strengthening wrongful conviction cases

The science of DNA testing is evolving, and that’s a good thing for wrongful conviction reform advocates like Fran Watson.

Watson, a professor at Indiana University Robert H. McKinney School of Law, leads the law school’s Wrongful Conviction Clinic. Things have changed a lot since the clinic secured its first exoneration in 2001, as scientists have developed new ways of testing DNA and matching it, or not, to suspected criminals.

Watson spoke on the history of exoneration work during a late-morning session of the Indiana State Bar Association Solo/Small Firm Conference on Friday. Speaking to an audience that included several alumni of the Wrongful Conviction Clinic, Watson traced the history of DNA exonerations and debunked some common myths about forensic tools law enforcement can use to identify or rule out suspects.

Fingerprint science, for example, cannot yet identify one specific individual. Watson told the story of a federal employee who was told he had just been given access to his building via his fingerprint. The problem, she said, was that the employee had been accessing the building with “his” finger for months, the system apparently believing his prints were someone else’s.

Individual hair samples likewise cannot individualize a suspect, Watson said. Each person has many different types of hairs on their heads, and what’s more, hair-based suspect matches have later been refuted. One such situation was the case in which Roosevelt Glenn and Darryl Pinkins were arrested, convicted and later exonerated of a 1989 Hammond rape.

But what is proving reliable is an emerging form of DNA science known as probabilistic genotyping, an algorithmic science that uses probabilities to match DNA markers to specific individuals, even if multiple DNA samples have been mixed. Watson admits it’s a complex science that only a handful of people fully grasp, but it was the tool that excluded Pinkins and Glenn from the DNA samples collected from the 1989 rape.

The importance of developing science, Watson said, is that jurors will believe what they are told the science tells them. Thus, if faulty science is unwittingly presented to jurors, they will rely heavily on that misinformation when deciding whether to convict.

“I’ll ask jurors, ‘Why did you convict?’ and they say, ‘The science said so,’” Watson said. “But the science didn’t say so.”

Reliable DNA testing is particularly important when it comes to proving harm, Watson said. Of the nine factors for admitting newly discovered evidence, she said the most difficult to prove is the ninth — that the new evidence would produce a different result.

But with conclusive DNA exclusions, such as was the case in Pinkins’ and Roosevelt’s case, the harm is “easy” to prove: the defendant has been accused, but the DNA clearly shows it wasn’t him. From there, Watson said, it becomes easier to prove that a different result would have come from the case had the new DNA evidence been available initially.

The consequences of a wrongful conviction are obvious but impactful, the professor said: families destroyed, innocent people incarcerated and guilty people walking free. Indiana has a comparatively good set of laws related to wrongful convictions, she said, noting the Indiana Constitution prohibits the suspension of the writ of habeas corpus.

Even so, reforms are still needed, Watson said. She praised the Indiana Legislature for enacting House Enrolled Act 1150, which compensates exonerated prisoners $50,000 for each year they were wrongfully incarcerated, during the 2019 General Assembly.

Watson also celebrated Indiana Rule of Evidence 617, which requires confessions to be recorded unless certain exceptions exist. That’s crucial especially in cases where confessions are alleged to be false, she said.

In the next decade, Watson expects DNA science to get stronger. She noted that both the FBI and the Indiana State Police have begun using probabilistic genotyping, while national organizations are working to develop more protocols, standardization and ethics regarding the accuracy of genetic testing.

“That means lawyers are going to have to learn new techniques,” Watson said, a positive development that she welcomes.

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