Iowa State University Professor Gary Wells says “forensic DNA”.has proven its value in solving crimes, and the proof is in the number of people it’s set free.

There are now over 180 people who’ve been exonerated because of DNA evidence, people who had been convicted and serving time for a crime they didn’t commit. After years of studying how victims and bystanders perform as police witnesses in criminal cases, the psychology professor says he’s formed a few conclusions about it. He says up to 80 percent of the cases which have been overturned by DNA evidence involved mistaken eyewitness identification. “Eyewitnesses error is the primary cause of the conviction of innocent people,” Wells says.

He’s looking for ways to help prevent those wrongful convictions, pointing out whenever you go after the wrong suspect in a crime, the real perpetrator is still out there, free. Wells has been working on ways to come up with better composite sketches that’ll accurately portray suspects, especially when multiple eyewitnesses are involved.