Beyond the Ken? Testing Jurors' Understanding of Eyewitness Reliability Evidence
Over the past thirty years, researchers have made substantial strides in understanding the workings and limitations of human memory. However, the application of these scientific advances to eyewitness identifications in the criminal justice system, though increasing, has been limited. Trial judges in most jurisdictions exercise their discretionary powers to exclude expert testimony about the reliability of eyewitness identifications. The most common rationale for excluding eyewitness identification expert witnesses is that their findings are not "beyond the ken" of the average juror.
To empirically test this "beyond the ken" rationale, an independent survey of potential jurors in the District of Columbia was designed to investigate whether jurors understand, as a matter of common sense, what makes some eyewitness identifications more or less reliable than others. The survey results, presented in this article by Timothy O'Toole, Richard Schmechel, Catharine Easterly, and Elizabeth Loftus, demonstrate that jurors misunderstand how memory generally works and how particular factors, such as the effects of stress or the use of a weapon, affect the accuracy of eyewitness testimony. In light of these findings, judicial practices of excluding expert testimony on the reliability of eyewitness identifications should be reexamined. Wrongful convictions, of which eyewitness identification error is the leading cause, will inevitably continue to result unless jurors can be better educated about these scientific findings.