For dramatic effect, there is no witness like an eyewitness who can point an accusing finger across a courtroom and say, “That’s the person who did it.” There’s just one problem with such identifications: Study after study has shown that eyewitness accounts can often be wrong.
Yet for the last 20 years, attorneys defending clients charged with crimes in Pennsylvania have been absolutely forbidden to offer expert testimony on the reliability of eyewitness testimony.
Last week, that changed. A divided state Supreme Court decided that its previous prohibition against such expert testimony would no longer apply. From now on, the testimony may be allowed at the discretion of the trial judge. It’s a wise move that reflects both scientific opinion and the practice of most other states and federal courts.
The case prompting this turnaround came from Philadelphia. Benjamin Walker was accused in 2005 of robbing college students at gunpoint in two separate robberies. In a consolidated trial, he was acquitted of one robbery and found guilty of the other and sentenced to a long prison term. The sole evidence linking the defendant to the robberies was eyewitness identification by the victims.
Prior to the trial, a motion was filed asking that an expert witness be allowed to appear to speak to the fallibility of human memory and the suspect nature of eyewitness testimony generally — but that was denied under the prior case law. On appeal, Superior Court affirmed the sentence. The Supreme Court, in a 4-2 decision, has now had second thoughts, remanding the case back to the trial court to consider if expert testimony on eyewitness identification is warranted.
The Pennsylvania justice system is the better for this decision. Eyewitnesses can be wrong and they can be right. How can juries sort it out? As Justice Debra M. Todd persuasively argued in the majority opinion: “One way in which fact finders may be assisted in making more accurate and just determinations regarding guilt or innocence at trial is through the admission of expert testimony.”