I recently received a copy of a law review article on the effectiveness of cross-examination for getting at the truth of eyewitness evidence. Prof. Jules Epstein explores in depth the efficacy of the “great engine of truth” as applied to eyewitness testimony, and reports that it falls far short. (Cite: Epstein, Jules, The Great Engine That Couldn’t: Science, Mistaken Identifications, and the Limits of Cross-Examination, 36 Stetson L. Rev. 727 (2007)).
Prof. Epstein frames the issue with a quote from the Supreme Court case of Watkins v. Sowders:
In Watkins v. Sowders, the Court found identification testimony no different from other categories of proof and cited Wigmore’s dictum in holding that cross examination would suffice to establish or debunk the reliability of the evidence as follows:
[W]hile identification testimony is significant evidence, such testimony is still only evidence, and, unlike the presence of counsel, is not a factor that goes to the very heart – the ‘integrity’ – of the adversary process.
Counsel can both cross-examine the identification witnesses and argue in summation as to factors causing doubts as to the accuracy of the identification – including reference to both any suggestibility in the identification procedure and any countervailing testimony such as alibi.
Epstein points out that “[a]t least two flaws are manifest in the Watkins
Given the significant incidence of mistaken-identification convictions, it is not clear if one can claim that such testimony does not go to the integrity of the adversarial process. Several decades of scientific study raise the question whether cross-examination can in fact secure reliable verdicts in cases of mistaken identification.
Following a detailed and extensively researched analysis, Prof. Epstein concludes that the highly revered truth-seeking tool of cross-examination, while perhaps effective at rooting out liars, is utterly ineffective at uncovering the truth when faced with a witness who is confident, but honestly mistaken about what he or she remembers — which accounts for the majority of cases in which mistaken identification has led to wrongful conviction.
In short, cross-examination was developed to counteract perjury, not genuine mistakes.
[T]hese accolades also show the limits of cross-examination and its inutility in confronting the truthful but mistaken witness, or in demonstrating the lessons of the science of perception, memory, and recall. A tool designed from its inception to root out liars is ill-suited for the task of exposing the risk or reality of mistaken identification.
Epstein also goes into some detail about the problems associated with getting the results of scientific studies on eyewitness memory in front of juries, without the aid of expert testimony. For example:
Q: Ma’am, you’ve told us that being robbed was a highly stressful event, correct?
Q: And you must know that the higher the stress, the more memory and perception get distorted. In other words, the more stress, the more it is likely that people make mistakes. You know that science has proved this, don’t you?
A: Look, I don’t know about studies. But I sure know what I saw. That man did it–this event was a powerful one, I’ll never forget it.
That, coupled with a prosecutor arguing the “she’ll never forget that face” line in closing, and a defense attorney is going to be hard pressed to sway a jury’s intuitive belief that the identity of the perpetrator is “burned in the mind” of the victim forever. That is, without an expert to testify to the uncontroverted findings of 30 years of social science research that counteract that widely held — but false — intuition.
Prof. Epstein makes a strong case for the admission of expert testimony on eyewitness factors, as well as detailed jury instructions, to counteract jurors’ “near-religious faith in the accuracy of eyewitness accounts.” He concludes that “ongoing reliance on cross-examination as a great engine will, sadly, contribute to the continued phenomenon of wrongful convictions based on eyewitness testimony.”