Innocence After Guilt Episode 4: Causes of Wrongful Convictions

According to the National Registry of Exonerations, there have been 3,337 exonerations since 1989 accounting for more than 29,500 years lost. In our quest for justice, how do we work to eliminate wrongful convictions? What has history taught us? What role has forensic DNA played since its emergence? In this video series we delve into the role of DNA testing in the United States in post-conviction work to exonerate the innocent and reassert convictions of the guilty.


In this episode, our experts discuss common causes of wrongful convictions. Some of the common reasons include mistaken eyewitness identification, false confessions, lying jailhouse informants, prosecutorial or state misconduct, and perjured testimony.




It’s important to note the mindset of both sides of the case throughout the trial and to consider that many erroneous convictions stem from jurisdictions that are overwhelmed and don’t have the resources, personnel, and budget required.


Fortunately, forensic science evidence is pretty accurate the vast majority of the time, however, the importance of presenting that evidence in a way that is understood by the jury cannot be understated. John Collins, who presents workshops around the country on ways to improve expert witness testimony skills and Tiffany Roy, who is a DNA consultant, share some common mistakes they see and ways an analyst can improve their communication skills. Peter Valentin also stresses the importance of not straying into areas of speculation, because the jury may not know the difference.


Mike Ware, Director of the Innocence Project of Texas, describes the case of Thomas McGowan, who was wrongfully convicted and served nearly 23 years in a Texas prison based, in part, upon faulty eyewitness testimony.


Around noon on May 7, 1985, a woman returned to her Richardson, Texas, home to find her television on the floor and pry marks on the door. Seconds later, she was assaulted by an African-American man who beat her severely and threatened her with a knife. He forced her to undress and tied a robe around her face and mouth. He put a work glove on his right hand, apparently to avoid leaving fingerprints, and tied her hands with the belt he had been wearing. He then raped the victim, drank a beer from the refrigerator and fled the house.


The victim called the police, who responded to the scene. She was transported to a local hospital, where a doctor treated her and collected swabs of semen found on her body.

The victim described the perpetrator to police as an African-American man, about 5’ 8” tall, with a mustache. At the police station on the day after the crime, officers first arranged a live lineup with three possible suspects and three “fillers.” The victim did not identify anyone. Ten days later, she viewed a highly unusual photo lineup with seven pictures. Three of the photos were black-and-white photocopies of photographs. Of the four color photographs, all were mug shots with the defendant holding a booking placard. One placard said “Garland Police Department” and three said “Richardson Police Department.” Since the crime happened in Richardson, the three photos with Richardson placards suggested that these three men had been arrested in Richardson. McGowan was pictured in one of these three photos – his photo was in the system because of a minor traffic violation. The victim said she “thought” he was the perpetrator, but the police officer administering the lineup told her: “You have to be sure, yes or no.” After the officer’s instructions, the victim said McGowan was “definitely” the man who attacked her.


When she testified in court, the victim recounted the officer’s instructions: “He said if I was going to say it was somebody, if I was going to say it was that picture, I had to be sure. He said I couldn’t think it was him. He said I had to make a positive ID. I had to say yes or no.” She also testified that the photocopied images stood out as different from the rest of the group. Her identification would be the central evidence against McGowan at his trial.


McGowan faced two separate trials connected to this incident: on December 4, 1985, he was convicted of burglary and on March 7, 1986, he was convicted of sexual assault. He received two consecutive life sentences.


McGowan appealed his convictions, arguing that an inadmissible argument was made by the prosecution during closing arguments and that testimony designed to bolster the eyewitness identification was improperly admitted. This appeal was denied. He sought the assistance of the Innocence Project, and his case was accepted in 2007.


The Dallas County District Attorney’s Office assisted Innocence Project attorneys in securing the biological evidence and moved quickly to approve DNA testing. In 2008, DNA test results showed that the sperm cells collected from the victim’s body during her hospital examination could not have come from Thomas McGowan or the victim’s boyfriend. McGowan was released from prison on April 16, 2008, and the Texas Court of Criminal Appeals granted his writ of habeas corpus on June 11, 2008, making his exoneration official.


Even more unfortunate, the person who had committed the crime was included in the original police line-up and was missed as the attacker, further underscoring how unreliable eyewitness testimony can be.


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