Chicago Tribune - May, 8th 2001

Truth is blurred by witnesses in Death Row cases

By Eric Zorn The eyewitness assured the members of the jury that she was "absolutely 100 percent sure" that Shareef Cousin was the man who had shot and killed her date outside a New Orleans restaurant in 1995.She was so positive, in fact, that on virtually no other evidence, jurors convicted Cousin and sent him to Death Row. They did so even though two athletic directors, his coach and several opponents said he had been playing in a youth league basketball game at the time of the murder. There was even a videotape of the game.Ultimately, related prosecutorial shenanigans inspired the Louisiana Supreme Court to reverse Cousin's conviction, after which the state dropped the murder charge.This example of the staggeringly persuasive power of eyewitness testimony is among the more troubling case histories in a study of such testimony released last week by the Center on Wrongful Convictions at the Northwestern University School of Law.After examining the cases of 86 former Death Row inmates who have been exonerated since the restoration of capital punishment in the mid 1970s, the study concludes that "erroneous eyewitness testimony--whether offered in good faith or perjured--no doubt is the single greatest cause of wrongful convictions in the U.S. criminal justice system."Eyewitness testimony played a role in 46 of the convictions--53.5 percent-- and was the only evidence against 33 of the defendants.False or coerced confessions, in contrast, played a role in only eight of the cases according to the Northwestern analysis. It identified misconduct by law enforcement officials in 17 cases.The study reinforces findings of the Center's June 2000 review of cases in which DNA evidence established the innocence of those convicted of a variety of crimes. Eyewitness identification testimony played a role in 76.1 percent of those cases, that study found.DNA evidence was the key in an earlier study by the FBI Crime Lab of more than 10,000 sexual assault cases in which police charged a suspect. Sexual assault cases nearly always involve the testimony of a victim who had a close look at the attacker. Yet DNA excluded the charged suspect in about 2,000 of the cases.This 20 percent witness error rate was similar to the 26 percent witness error rate found in an informal National Institute of Justice survey using data from private forensic labs.In test situations, psychologists have shown that what we remember after stressful events is not always what we've seen, and those who question us afterward can alter such "memories" deliberately or unintentionally."Without even trying to, a police officer can communicate to a witness what he thinks happened," said University of Washington psychologist Elizabeth Loftus, who has written extensively on human memory. "When the witness reflects this, the officer reinforces it. They can then both become very, very confident about something that's false."Rob Warden, executive director of the Center on Wrongful Convictions, said the study, which he wrote, illustrates a need for police and the courts to take a more scientific approach to eyewitness testimony.For instance, when police hold lineups, all participants should closely match the description of the suspect and present themselves to the witness one by one in the presence of observers who don't know the "right" answer."The system needs to treat witness testimony as carefully and skeptically as it treats trace physical evidence," Warden said. "Because both can be easily contaminated."Not to mention intentionally contaminated or downright invented, which seems to be what happened in the six Illinois Death Row exonerations that involved discredited eyewitness testimony. (We say "seems" because the state seldom thoroughly reviews its own blunders to discover the root causes of a wrongful conviction).Yet judges now routinely exclude from trials the testimony of expert witnesses in memory and witness fallibility. Warden and Loftus (who is such an expert) argue related expert testimony should be encouraged by the courts in cases that rely strongly on witnesses."When you hear someone say, `This is how it happened' and they don't seem to have any motive to lie, it's very hard to resist believing them," Loftus said. "But the more people are made aware of the problems with eyewitness testimony, the more they'll refrain from uncritically accepting any claim, no matter how dubious."