Expert Witnesses Challenge Eye Witness

Part I: Illinois Supreme Court paves the way to Challenge Eyewitness Identification with Experts: Implications for Civil Litigation

In January, the Illinois Supreme Court took a monumental step forward in allowing expert witness evidence to be considered a viable challenge to eyewitness identification. See, e.g., Karen Daniel, “Illinois embraces eyewitness expert testimony,” Center on Wrongful Convictions, Bluhm Law Clinic, Northwestern University School of Law, Jan. 22, 2016.

While People v. Lerma, the case settled by Illinois’ highest court,  the holding may have farther-reaching impacts with respect to expert opinions on eyewitness evidence in general. Specifically, this may be used as example for litigators dealing with witnesses in the civil area as well. This article explores the Illinois ruling and discusses the import of using expert witnesses to challenge eyewitnesses in civil litigation.

Regardless of whether a case is criminal or civil in nature, the nation’s courts have not accepted the approach to when expert witness testimony should be admitted in response to eyewitness identifications. The ruling in People v. Lerma provides attorneys with an opportunity to cite a high court precedent that can be applied to civil matters as well, and it may pave the way for other state and national courts to follow that trend.

(A). What the Court Said: Why Eyewitness Testimony is Problematic & How Experts Can Help Juries Understand these Flaws: According to the Illinois Supreme Court, “[I]n the [past] 25 years…, we not only have seen that eyewitness identifications are not always as reliable as they appear, but we also have learned, from a scientific standpoint, why this is often the case. Accordingly,…today we are able to recognize that such research is well settled, well supported, and in appropriate cases a perfectly proper subject for expert testimony.” Id. The Court argued that when the trial court excluded the defense motion to introduce expert evidence regarding eyewitness testimony, it prohibited the jury from understanding a number of important, valid, scientific considerations about flaws in eyewitness identifications. For example, had the expert evidence been involved, the jurors would have been informed that there are a number of “’common misperceptions’ that exist regarding the accuracy and reliability of eyewitness identifications.” Such as “documented scientific dings, all of which are beyond the common knowledge of the average layperson: that the witness’s level of confidence does not necessarily connect to the accuracy of the identification; that numerous factors can undermine the accuracy of an eyewitness’s identification, including the stress of the event itself,… passage of time, the “forgetting curve,”…exposure to post event information, nighttime viewing,..that eyewitnesses tend to overestimate time frames; and that cross-racial identifications tend to be less reliable than same-race identifications.” Id.

(B). Civil Application of Lerma: Undoubtedly, some of the same flaws that exist in criminal cases involving eyewitnesses are often present in civil trials as well. For instance, “Memory plays a central role in civil litigation, as well…. . Although researchers and legal scholars are most familiar with problems of witness reliability in criminal cases, the demands on witnesses’ memories are often more daunting in civil litigation…”. Charles A. Weaver, III, “Eyewitness Memory in Civil Litigation,” American Psychology-Law Society News, Oct. 2013. Moreover, jurors regard eyewitness identification evidence as being extremely persuasive in civil litigation. See Marc Green, “Errors in Eyewitness Identification Procedures,”, 2013. Furthermore, unlike in criminal cases, few restrictions exist with respect to how a witness may be prepared before making identifications, which can make eyewitnesses more susceptible to questionable and/or suspect methods that attorneys may employ to sway a witness’s testimony by using suggestive and persuasive techniques. See Weaver, supra. Clearly, the problems with potentially inaccurate or unreliable eyewitness testimony are not limited to the criminal realm and, if anything, may be even more of an issue in civil cases.

To date, most jurisdictions have only implemented haphazard ways of dealing with the inadequacies of eyewitness identifications. See, e.g. Sarah Kellogg, “A Flawed Record: The Fragility of Eyewitness Testimony,” Washington Lawyer, 2014. People v. Lerma provides an important starting point for challenging such testimony through the use of expert witnesses. Unless or until more uniform standards are adopted with respect to eyewitness evidence, attorneys should continually avail themselves of expert witnesses, who currently may provide the most successful way of breaking down problematic eyewitness identifications. In order to strengthen their positions, attorneys can cite Lerma as a judicial precedent to establish the fact that in a world where eyewitness evidence is both highly compelling to jurors and fraught with gross inaccuracies, at least one high court has recently acknowledged such inaccuracies and held that expert testimony is a legitimate and important way to challenge such identification evidence.

Part II:  Using Expert Witnesses to Break Down Eyewitnesses in Civil Litigation: The Green Approach

Part I of this series explored the recent holding of the Illinois Supreme Court in People v. Lerma, a case involving using expert witnesses to challenge eyewitness identifications in criminal court. The Lerma court held that an expert opinion, which would have pointed out the myriad flaws in eyewitness testimony, should have been included in the evidence and was a valid and significant way to help juries understand the flaws of eyewitness identification evidence. This part discusses how attorneys in civil cases can refute eyewitness testimony through expert witnesses.


There is substantial literature that examines how and why eyewitness identifications can be highly inaccurate. Many experts, from psychologists to legal scholars, have addressed this matter, in an attempt to help train lawyers and experts to know what questions to ask eyewitnesses, as well as what issues to raise and what arguments can help jurors understand the fragility and flaws inherent in such identifications. What follows is a discussion of strategic approaches that can aid attorneys and experts in exposing such flaws and successfully challenging eyewitness testimony in civil cases.

Grounds for Challenging Eyewitness Evidence: The Green Approach: Dr. Marc Green, a P.h.D. in experimental psychology with over 42 years of experience as an expert in disproving eyewitness identifications, writes about some of the basic scientific problems that exist with respect to eyewitness testimony. As Green explains, there are three general flaws with eyewitness identifications that attorneys (via experts) should address: (1). Poor encoding, (2). Memory problems, and (3). Bias. See Marc Green, “Errors in Eyewitness Identification Procedures,”, 2013.

  1. Poor Encoding: One ground upon which expert witnesses may be able to gain ground against an eyewitness involves encoding, or how a witness’s brain initially perceives an event. See id. This approach involves questioning and challenging the eyewitness’s visibility at the time an event occurred. Factors for attorneys and expert witnesses to consider in this vein include arguing that the lighting at the time of the event was poor, that the duration of the event (and the witness’s involvement in the incident) was too brief to give rise to an effective/accurate identification, that the witness was too far away to form an accurate opinion, and that perception is affected by known, scientifically documented tricks that the mind plays on a witness.
  1. Faulty Memory: Green discusses the problem of proper eyewitness recollection, which affects the ability to correctly identify a face, product, figure, or sequence of events. See id. He explains that “Memory has several quirks which affect reliability, including 1) low resolution (a remembered face is not as clear as one actually viewed), 2) the tendency for memories to be constructed so that missing information is supplied from expectations/biases or from an external source ([the media], other witnesses,…etc.) or from other memories and 3) systematic perceptual distortions in memory (small sizes grow and large sizes shrink, colors are remembered as brighter, etc.).” Id. All of these issues should be raised by attorneys and experts in the field, and mentioning them in civil cases is critical.
  1. Bias: Although many eyewitnesses strive to be correct in their identifications, their unconscious or subconscious biases can play a major role in how they perceive and provide information. For example, in People v. Lerma, the Court expressed that eyewitnesses have much more difficulty in providing accurate identifications in cases involving someone who is a different race than the witness. Moreover, parties who examine eyewitnesses may prejudice eyewitnesses to make a specific identification. See Green, e.g., supra. Witnesses often look to friendly examiners for confirmation and may become more definite in their identifications if they feel the examiner is trying to lead them in a certain direction, agrees or disagrees with their initial thoughts, or has a specific opinion of their own that they wish for a witness to consider. See id. Green explains the impact of this bias: “[T]he eyewitness might look for a sign of confirmation, real or imagined. Some personality types constantly seek approval from authority figures… . They are likely to seek affirmation in feedback from the examiner….[Moreover,] the examiner can easily influence witness confidence… . If the examiner says ‘good’ or ‘um hmm,’ after the choice, the eyewitness will feel more confident and likely later express a stronger belief in his/her accuracy. This can be crucial because juries look at not just the identification, but also at the witness’s certainty. In fact, one study found that witness confidence is about the only aspect of an identification that jurors consider… . This is…one of the reasons the correlation between eyewitness confidence and accuracy is low…”. Id. The correlation between eyewitness confidence and eyewitness accuracy is of great import: while juries associate a confident witness with an accurate one, studies have proven that such is not the case, and that furthermore, the relationship between the two is minimal. See id. Attorneys should utilize experts to prove such disparities and to explain that a witness who seems positive about their identification is not necessarily an accurate or reliable witness and that often, the reverse is the case.

Using expert witnesses to challenge eyewitnesses is undoubtedly one of the best ways to refute such identifications. Dr. Green’s suggestions provide valuable strategies that attorneys and their experts can employ to make these challenges to eyewitnesses, and practitioners should take note of the techniques discussed herein, applying them as often as possible, to help prove what science has already demonstrated but what juries are generally unaware of: that eyewitness evidence is as fallible as human perception, and that errors in such evidence are more common than a jury may initially realize.