Constructing Evidence and Educating Juries: The Case for Modular, Made-in-Advance Expert Evidence about Eyewitness Identifications and False Confessions

Over the last several decades, research psychologists have entered the courtroom with increasing frequency to testify on behalf of criminal defendants. Their role has primarily been to show how social-science evidence complicates the conventional wisdom about certain kinds of critical and often-used evidence. These witnesses challenge, and sometimes even debunk, commonsense views about categories of evidence that juries tend, on the whole, to find very persuasive, like eyewitness identification testimony and even that so-called "queen of proofs," the confession.1 These experts educate judges and juries about the substantial body of research that shows, for example, that eyewitnesses-even those who have a great deal of genuine confidence about their own accuracy-are sometimes mistaken when they identify someone as the perpetrator.2 They teach the fact finders that memory operates not at all like a point-and-shoot camera; rather, honestly held beliefs about what a witness claims to have seen or experienced may be distorted, inaccurate, or even completely wrong.3 They describe the dangers of certain lineup procedures that may increase the chances that a witness makes an erroneous identification.4 They describe the reality, surprising to many, that innocent suspects under interrogation by the police sometimes really do confess to crimes in which they actually played no role at all.5The judicial reception of these forms of psychological evidence has been stuttering and somewhat rocky, but overall it is fair to say that there is growing acceptance of the legitimacy of these kinds of expertise. In fact, a number of courts have held that when an eyewitness identification by a stranger is at the heart of the prosecutor's case, the trial court's exclusion of a qualified defense expert who could have educated the jury about relevant social-science findings about the danger of mistaken identifications can even be reversible error.6 Courts in recent years have shown increasing concern and interest in the problem of unduly suggestive lineup procedures as well.7 For false-confession evidence, the trend line remains somewhat more uneven; while some courts do continue to exclude the evidence, often on the grounds that it is unnecessary or invades the province of the jury (by indirectly opining on credibility), many others do permit such expertise.8The recent increased focus on and knowledge about wrongful convictions have spotlighted the importance of these kinds of psychological evidence. The rise of DNA evidence and the concomitant Innocence Movement have exposed the significant dangers of erroneous eyewitness identifications and false confessions, among other kinds of evidence. In a close look at the first several hundred DNA exonerations, Brandon Garrett found that around three-quarters of the cases involved some form of mistaken eyewitness identification.9 False confessions were less commonplace but still far from rare, appearing in nearly one-sixth of the cases he examined.10This prevalence of mistaken eyewitness identifications and false confessions among known wrongful convictions strongly suggests that fact finders sometimes risk overvaluing or misinterpreting these kinds of evidence. By educating the jury about social-science research, expert psychological evidence may give the jury better tools for assessing probative value more accurately. Teaching about risk factors for erroneous identification or mistaken confession may enable savvier assessment of these kinds of proof in the particular case-and helping fact finders to assess these kinds of evidence with an informed, critical eye may even help reduce wrongful convictions.That said, expert psychological evidence is only one possible method among several for attempting to reduce wrongful convictions based on erroneous eyewitness identification or inaccurate and false confessions. Moreover, realistically it is simply not an approach that can feasibly be used in the very large number of cases in which these forms of evidence play a starring role. …