DNA exoneration: Redeeming the wrongfully convicted

Going to prison for a crime you did not commit is a nightmare that has inspired great fiction, from “The Count of Monte Cristo” to modern Hollywood takes such as “The Shawshank Redemption.”

Meanwhile, in the real world the introduction of modern genetic testing into the criminal justice system has added a new twist to these old themes, providing for some a way out from behind bars — through an exoneration process that leads from the laboratory to the courtroom.

DNA evidence has saved the lives of those on death row and freed others from long prison terms. Since the first convicted inmate was exonerated using DNA evidence in 1989, there have been 316 DNA exonerations nationwide, with the vast majority since 2000 ending in freedom for the convicted. Today, all 50 states have laws that, to varying degrees, permit convicts to access DNA tests — even decades after what may have been a wrongful conviction.

Lawrence Kobilinsky, chair of the sciences department at John Jay College of Criminal Justice in New York, said that the public, as well as judges and juries, considers DNA testing to be “the gold standard” for proof that, if produced, can trump other types of evidence.

In addition to its potential to free the innocent, DNA testing can help identify a crime’s true culprit. Nearly half of DNA exoneration cases lead to someone other than the falsely convicted individual.

Kobilinsky cautioned that DNA testing is not 100 percent foolproof, though. Because humans must collect and test DNA samples, the process is susceptible to human error. “People can pipe material into the wrong well, or they can mislabel samples. You cannot have an expert go on the stand and say, ‘We never make mistakes,’ because that’s not real life,” he says.

Still, Kobilinsky said efforts by advocacy groups have “revealed to convicts, felons and criminals that there is a way out of prison.” The professor added: “But you can get a D.A. [district attorney] who doesn’t want to have a case opened up. They have a conviction under their belt. Why would they want the case overturned? [Yet] a D.A. should be cognizant of their mission, which is justice — not just winning a case.”

As a group, these exonerated individuals have served more than 4,000 total years in prison, according to the Innocence Project. The average among them was locked up for 13 years and was found guilty at the age of 27.

Nine percent actually entered a guilty plea for a crime they didn’t commit. Six percent were serving on death row, with another 5 percent charged with capital crimes but not sentenced to die.

Many jailed convicts remain unable to access tests that could prove their innocence. In terms of racial disparity, 62 percent of the freed prisoners are African-American.

DNA exoneration cases involve irrefutable evidence that the suspect was wrongfully convicted, and can spring from a number of causes, including bad lawyering and government misconduct, as well as the following relatively common reasons:

Flawed forensics — This type of scientific mistake occurred in the process of convicting around half of those ultimately exonerated through DNA testing. Botched forensic techniques include hair microscopy, firearm analysis and shoe print comparison. Some cases are led astray due to misconduct by forensic scientists.

Eyewitness misidentification — Testimony based on false identification of the suspect was the cause in almost three-quarters of DNA exoneration cases, meaning it was the most frequent error. Forty percent of these mistakes involved cross-racial identification in which the eyewitness picked out a suspect belonging to a different racial group.

False confessions — About a quarter of the DNA exoneration cases contained false confessions, which are a disproportionately high factor in homicide cases. Advocacy groups say police should record the entirety of every interrogation.

Unreliable informants — Almost one-fifth of the cases stemmed from a wrongful conviction that hinged on testimony by a “snitch,” often given in exchange for better treatment by law enforcement or in exchange for dropping charges.

There are about six exoneration cases that didn’t involve the use of DNA testing to shed light on a wrongful conviction. Thus, only a small fraction of cases in which the convict was set free involved nonbiological means.