Science has seriously compromised police and prosecutors' most cherished tool - eyewitness testimony.
What the Innocence Project has found after securing the reversal of 126 convictions using DNA evidence is that 80 percent of the original convictions were based on eyewitness testimony.
Psychologists led by Gary L. Wells of Iowa State University ran an experiment which showed that what police tell them about their recollections can affect people's faith in what they saw.
It is counterintuitive to suggest that what or who a person saw could be wrong. We trust what we see, don't we? Why not what others say they saw? But consider that DNA analysis has shown eyewitnesses wrong 100 of 126 times it has been applied - a breathtaking number.
Dennis Maher, 42, spent 19 years in prison in Massachusetts after not one but three rape victims said he was the perpetrator. He thought he would die there. He continually proclaimed his innocence, yet had to attend group therapy sessions and listen to child molesters and rapists talk about their dirty deeds, as if he were one of them.
Another path to bad convictions are bad confessions, those resulting from unrelenting police pressure on certain personalities. Police clear cases with these confessions, but they damage the integrity of the justice system. Until the cases in Britain in which accused terrorist bombers were shown to have been wrongly convicted, it was also difficult to disbelieve a confession, or believe in one that was recanted.
Eddie James Lowery, who spent 10 years in a Kansas prison, thought he would never recover the good name he lost 20 years ago when he was convicted of rape. After police broke him down, with methods now eschewed by many departments, he falsely confessed. To be paroled, he had to falsely confess again in order to get into a required pre-release treatment program. Outside he spent years as a registered sex offender, even though he wasn't.
Science has put more stringent demands on police and prosecutors, even as it gives citizens who might be jurors and judges reason to question. Eyewitness evidence is hardly infallible.