By Brandon L. Garrett, a professor at the University of Virginia School of Law and author of "Convicting the Innocent: Where Criminal Prosecutions Go Wrong.”
The Court has decided two cases involving eyewitness evidence in two days, both 8-1 rulings, but with seemingly inconsistent attitudes towards eyewitness identification procedures. The dueling cases touch more on general conduct of police and prosecutors than on core issues regarding reliability of eyewitness memory. But they provide a fascinating look at how the Justices may evaluate trial evidence in criminal cases.
In the first case, Smith v. Cain, a "single witness" linked Juan Smith to five murders he was convicted of in New Orleans. It was an easy case, with seven Justices joining Chief Justice Roberts' short, clear opinion. At trial, the lone witness said he saw the attacker face to face and was sure Smith was the one. However, it emerged in habeas proceedings that the prosecutor never told the defense that the single witness told police early on that he did not think he could even make an identification of the killer. Maybe he was not an eyewitness at all – just a witness. Police notes documented how in the days right after the crime, he said he “could not ID anyone because [he] couldn’t see faces” and “would not know them if [he] saw them.” Everything hinged on this one witness; there was no other evidence.
The Justices readily concluded that such powerful evidence undermining the testimony of the state's only evidence was "material" and there was a "reasonable probability" that it would have made a difference at trial. This was serious misconduct.
In contrast, Justice Thomas, who wrote a lengthy dissent, emphasized how months after the crime, the witness (who he called an “eyewitness”) saw Smith's photo and said, "This is it. I’ll never forget that face." Justice Thomas emphasized that the witness was “confident.” Yet consider the vast body of research on eyewitness memory. The memory of an eyewitness degrades - in a matter of hours, not days. And the the confidence of an eyewitness at trial does not mean much at all as to its accuracy; that much is crystal clear from decades of social science research.
In the second case the Court decided, the witness did see something, said she saw something, and identified the defendant at the crime scene in person (although not at a photo array and she was not asked to identify him trial). She was a single eyewitness. The vote count was flipped. In Perry v. New Hampshire, it was the lone dissenter who recounted the lessons from three decades of research on eyewitness memory. Justice Sotomayor argued that whether or not police intend to set up an identification procedure, the court should conduct the due process “reliability” analysis. Justice Sotomayor cited to the noteworthy New Jersey Supreme Court decision last fall creating a social science framework to regulate eyewitness memory, to the fine briefing by the American Psychology Association, and to my research on the role that eyewitness misidentifications play in wrongful convictions. (In reading the trials of the first 250 people exonerated by DNA tests, I saw countless examples of eyewitnesses who were certain at trial and claimed they would never forget that face - but DNA tests showed they were wrong.)