That Pesky DNA

In these pages, we’ve written about the impacts of faulty memory on criminal cases. We’ve talked about faulty lie-detectors and faulty software used to find lies in “emotional speech.” We have also written about false confessions. We’ve even written about unexpected reactions to violent situations, reactions that, as it turns out, do not fit the TV prescription for guilt or innocence.

Since these behaviors are often fundamental to the arrest and conviction of criminals, they are essential to any consideration of the criminal justice system. When they go wrong, justice is thwarted.

That’s where DNA comes in. It wasn’t that long ago that DNA testing was introduced into criminal proceedings (and I recall my co-author asking at the time what cops could do to challenge it). Now, some twenty plus years later, it is “taken for granted” as a scientific way to show the guilt or innocence of someone accused of a crime.

As the Innocence Project reports, since 1989 there have been 281 post-conviction exonerations in the U.S. In 45% of those cases, the DNA identified the true suspects or perpetrators. According to the Innocence Project, moreover, we find that:

About 80 percent of wrongful conviction cases overturned through DNA testing were single perpetrator crimes. About 75 percent of the single perpetrator crimes involved eyewitness misidentifications (60 percent of the total), and about 75 percent of them were non-homicide cases. In about half of the single perpetrator cases, the real perpetrator has been identified.

Sounds pretty much like a slam dunk. Find the DNA and let somebody wrongly accused go free. Turns out it’s much more complicated. You knew that, right?

Let’s consider the case of Michael Morton, who served 25 years in Texas prison for his wife Christine’s murder. Morton has consistently maintained his innocence, saying his wife was murdered by a third-party intruder. He said that DNA testing would prove it.

For more than six years, the Innocence Project has been seeking access to DNA testing on a stained bandana that was found on an abandoned construction site approximately 100 yards from the crime scene… On June 20, 2011, a testing laboratory issued a report finding that the bandana contained the DNA of a man other than Michael, along with Christine’s blood and hair. The male DNA was put though the national DNA database and has been linked to a convicted offender.

Why did it take so long? Texas District Attorney John Bradley blocked the introduction of DNA evidence. Worse, it now appears that other evidence was suppressed. Exculpatory evidence that pointed toward a third-party intruder. It seems that the prosecution had already made up its mind that Michael Morton had beaten his wife to death because she refused to have sex with him on his 32nd birthday.

Ok, not as bad as the “witch” accusations and “sex-starved-she-devil” tag that Italian prosecutor Giuliano Mignini put on Amanda Knox, but… That pesky DNA turned up there, too, didn’t it?

More interesting to this crime writer, though, is what such old, old, old evidence does to the prosecution of the criminal case. As Brandi Grissom, writing for The Texas Tribune, notes in her spot-on coverage of the Morton case, “Key witnesses may have moved or died, documents could have disappeared, and evidence-collection standards are now much stricter.”

The new defendant’s lawyer, Russell Hunt, Jr. — who has the task of defending his client against a 25-year-old crime — concurs, saying: “People change over time. People’s memories change over time… Physical evidence gets moved. Physical evidence is stored in different ways.”

It won’t be a slam dunk. But it should have been. Should have been, except for cops and prosecutors making up their minds and putting blinders on to prevent any doubt from creeping in. Stop it, already.