Who are you going to trust? Science or your lying eyes?
Eyewitness testimony is widely understood to be highly probative of guilt and is among the most damaging and effective evidence the prosecution may use in making its case against a defendant. However, eyewitness reports are subject to their own frustratingly difficult array of inherent bias and mistake. This is especially true in cases where the eyewitness is stressed by the events that he or she witnesses.
In a new report by the National Research Council (see their press release here), the National Academies have made a number of recommendations to assist with standardizing best practices for obtaining and using eyewitness testimony. These include recommendations specific to law enforcement personnel, and other recommendations specific to the courts. The report recommends the use of double-blind lineups, where both the witness and the officer directing the examination are kept unaware of which individual is the prime suspect. Standard instructions, videotapes of lineups, additional training, and an inquiry into the witness’ confidence are among some of the other recommendations in the report.
In the court setting, the National Research Council emphasizes the importance of utilizing the scientific method to enhance the accuracy and reliability of eyewitness testimony. Specifically, it recommends that expert testimony be made available in mistaken identity cases to explain the relevant research pertaining to eyewitness memory and identification. This research has proven to be counter-intuitive.
Until recently, Pennsylvania jurisprudence proved to be a complete bar against the use of expert testimony for explaining the vagaries of eyewitness testimony. In decision after decision, Pennsylvania jurists, despite common practice in federal courts since 1977, held that eyewitness experts would impermissibly intrude upon the jury’s role in making findings of credibility. As of 2014, only Pennsylvania, Kansas, and Louisiana had per se bans on expert testimony regarding eyewitness testimony.
Recognizing that the vast majority of courts had shifted away from Pennsylvania’s steadfast position, in May of this year, the Pennsylvania Supreme Court abandoned the per se ban in Commonwealth v. Walker, 92 A.3d 766 (Pa. 2014). Pennsylvania now allows expert eyewitness behavioral testimony on the discretion of the trial judge, determined by the familiar Pa.R.E. 702 standard.
Eyewitness testimony is not infallible, and this report breaks important new ground in establishing how eyewitness testimony can be accurately deployed to prove or disprove a case. While Walker is a first-step for enhancing the reliability of jury decisions predicated on eyewitness testimony, hopefully this report will prove useful in advancing more “best practices.”