Expert Testimony on Eyewitness Reliability In most documented cases of the conviction of innocent persons, mistaken eyewitness identification is the culprit. Regardless, many continue to believe that eyewitness identifications and testimony are generally reliable and persuasive forms of evidence, and that any inaccuracies are readily detectable by the layperson. However, recent scientific studies show that eyewitness accuracy is affected by numerous factors, including identification procedures commonly used by police. An expert witness can educate the trier of fact on the reliability (or lack thereof) of eyewitness identifications, the effects of various police procedures, and ways to improve the accuracy of these procedures. It has thus become very important for defense counsel and others to obtain a working knowledge of the results of the recent studies, to understand the relationship between the admissibility of eyewitness identifications and the experts' findings, and to know when and how to present expert testimony on eyewitness identifications.

Admissibility of Eyewitness Identification Testimony In United States v Wade, 388 US 218 (1967), the United States Supreme Court acknowledged the inherent unreliability of many eyewitness identification procedures and examined the relationship between these procedures and eyewitness identification testimony. Because police procedure was known to affect the accuracy of the identification, crossexamination of the eyewitness was often insufficient to assure reliability. Thus, the Wade Court held that the accused has a Sixth Amendment right to counsel at a post-indictment corporeal lineup. Where counsel was not present during the procedure, testimony concerning the procedure is per se inadmissible at trial. Gilbert v California, 388 US 263 (1967). Nonetheless, the accused may not have a right to counsel at pre-indictment photographic identification procedures unless there are "unusual circumstances" and the accused can be readily produced by the police. People v Jackson, 391 Mich 323 (1974); People v Kurylczyk, 443 Mich 289 (1993) cert den 510 US 1058 (1994). Thus, in many cases, defense counsel's role in assessing the reliability of identification procedures may be limited. Moreover, unnecessarily suggestive identification procedures, whether pre or post-indictment, may constitute a denial of due process rights. Stovall v Denno, 388 US 293 (1967). The rule of Stovall was extended to photographic identification procedures in Simmons v United States, 390 US 377 (1968). In fact, photographic identification procedures were found to be particularly dangerous since an initial mistaken photo identification may "color" any subsequent corporeal identification. Where the procedures are unnecessarily suggestive or conducive to mistaken identification, a hearing must be held to determine if an independent basis for the identification exists. Several factors determine whether the eyewitness identification has an independent basis assuring its reliability. People v Kachar, 400 Mich 78 (1977). These factors are:

   1.the witness's prior relationship with the accused;

   2.the witness's opportunity to observe the offender and the offense; 

   3.the length of time between the offense and the identification; 

   4.the accuracy of the witness's description of the offender prior to the identification procedure in light of the

     defendant's actual appearance;

   5.any prior identification or failure to identify the defendant; 

   6.any identification of a person other than the defendant as the culprit prior to the suggestive procedure; 

   7.the nature of the offense and characteristics of the witness; 

   8.idiosyncratic features of the defendant. 

Although many studies of eyewitness accuracy indicate that several of these factors are important, the studies isolate many others that are not among the Kachar factors. Also, judges and jurors may rely on "common-sense" factors to assess reliability and credibility. For example, although the witness's certainty has been found to be a weak indicator of accuracy, judges and jurors may rely heavily on it when assessing the reliability and credibility of the identification. See also Manson v Braithwaite, 432 US 98 (1977) (eyewitness confidence constitutionally permissible factor in assessing independent basis). In People v Franklin Anderson, 389 Mich 155 (1973), the Court reviewed the basis of the holdings in the "Wade cases" and considered their application to cases involving photographic identification procedures. The Court relied on studies showing that eyewitness confidence had little relation to accuracy, the stress of events could severely distort memory, and identification procedures encouraged "positive identification of things merely similar." Id., at 205. The Franklin Anderson Court took judicial notice of four procedural and psychological factors involved in eyewitness identifications:

   1.the natural and usually necessary reliance on eyewitness identification of defendants by the police and prosecution; 

   2.the scientifically and judicially recognized fact that there are serious limitations on the reliability of eyewitness identification of defendants; 

   3.the scientifically and judicially recognized fact that frequently employed police and prosecution procedures often(and frequently unintentionally) mislead eyewitnesses into misidentification of the defendant; 

   4.the historical and legal fact that a significant number of innocent people have been convicted of crimes they did not commit and the real criminal was left at large." Id., at 172. 

However, despite judicial recognition almost 25 years ago of the vagaries of eyewitness identification evidence, courts have only recently shown a willingness to allow expert testimony on eyewitness identification.

In 1983, a state supreme court first found reversible error in the exclusion of expert testimony on eyewitness identification. State v Chapple, 135 Ariz 281; 660 P2d 1208 (1983). Cf. People v Hill, 84 Mich App 90 (1978). California and other states soon followed suit; however, decisions were and continue to be case-specific. The eyewitness identification had to be a key element in the prosecution's case and not substantially corroborated by other evidence lending it independent reliability. The defendant was required to present a qualified expert to testify on the specific psychological factors that could have affected the accuracy of the witness's identification but would not be known or understood by the jurors. See People v McDonald, 37 Cal 3d 351, 208 Cal Rptr 236 (1984); United States v Smith, 736 F2d 1103 (CA 6) cert den 469 US 868 (1984). Some decisions required the defendant to present an alibi defense before expert testimony would be considered. State v Moon, 45 Wash App 692, 726 P2d 1263 (1986). But cf., People v David Allen Carson, where failure to appoint an expert was not error because the indigent defendant was able to present an alibi defense [___ Mich App ___ (#159501, 6-4-96) opinion vacated and conflicts panel convened on another ground, ___ Mich App ___ (6-14-96)].

In general, courts have advanced three grounds for exclusion of expert testimony: doubts about the scientific validity of psychological experiments; doubts about the effect of the testimony on the jury (invasion of the jury's province, juror confusion, prejudicial effect); and continued confidence in cross-examination and jury instructions to protect the defendant from the inherent weaknesses of eyewitness identification testimony. Recent studies of eyewitness identification and related police procedures suggest that these grounds for exclusion may no longer be valid in every case. The procedural and evidentiary requirements for admission of expert testimony will be examined later in this article. A summary of the findings of recent psychological studies will assist counsel to successfully argue for the admission of such testimony.

Summary of Eyewitness Identification Research The number of studies on the factors influencing eyewitness identification has grown quickly during the last two decades.

1 A close examination of individual studies reveals that their conclusions are based upon sound scientific methodology.

2 Moreover, researchers reject the common argument that "laboratory conditions" don't mirror the circumstances of real crimes and thus are inherently inaccurate. Many point out that lab conditions produce higher witness performance than what would occur during an actual crime. The actual identity of the "culprit" in the experiments is known, and identification responses of subjects can be evaluated for accuracy. In general, the studies reveal that several factors not included in Kachar influence the accuracy of eyewitness identifications and suggest that alternative police procedures could improve their accuracy.

3 Witness Factors One group of findings focuses on factors influencing the witness's ability to perceive and recall the offender's face.

4 "Stable characteristics" such as sex, race, intelligence, and certain personality characteristics are not useful predictors of identification accuracy. Age, however, was found to be significant: younger and older witnesses were generally less accurate than other adults. On the other hand, studies of "malleable characteristics" such as the witness's state of mind or intoxication produced mixed results. Expectation of a subsequent lineup while viewing the crime had little effect on accuracy, and similar results were reached in tests involving eyewitnesses with training in identification, such as bank tellers. Although alcohol intoxication is potentially an important factor, few studies have examined the effects of varying levels of intoxication. Several aspects of the witness's memory can be relied on as indicators of accuracy and reliability.

Greater detail in the description of an offender's face increases the accuracy of identifications only slightly. Similarly, a witness's memory of peripheral details is inversely related to the accuracy of offender identification: where the witness was able to testify in great detail about the circumstances surrounding the offense, more positive identifications were made, but these identifications proved less accurate. Perhaps most importantly, the witness's confidence in his or her ability to identify the offender during a police procedure is unrelated to the accuracy of the identification. Franklin Anderson, supra, 389 Mich at 174-175, 217-219. This may be particularly damaging since studies also suggest that the perception of the witness's confidence in his or her identification is relied upon by jurors and judges to assess the witness's credibility.

Offender and Offense Factors In addition to "witness factors," factors involving the offender and the offense may also affect the accuracy of the identification. "Distinctive targets" -- highly attractive or highly unattractive offenders -- are more often correctly identified and less often mistakenly identified. Conversely, a change in physical appearance of the offender and the use of "disguises" greatly affect the accuracy of later identifications. In particular, changes in hairstyle or the use of a hat to conceal the hairline was found to greatly hamper the ability of eyewitnesses to make accurate identifications later. Factors surrounding the offense itself proved to be the most important predictors of accuracy. Not surprisingly, the longer the eyewitness is exposed to the offender, the more accurate the description.

5 "Weapon focus" also proved to be a real phenomenon affecting eyewitness accuracy: eyewitnesses were significantly more accurate where no weapon was used during an offense. Levels of accuracy increased slightly where a weapon was only implied. "Crime seriousness" also plays a role: in studies involving the theft of various objects, results showed that, in general, the more expensive the item stolen, the more accurate the witness's description of the alleged thief. Bystanders were found to be slightly more accurate than victims.

6 Interestingly, studies have found that race and gender play a role in the accuracy of facial identification. 7 Cross-race identifications were found to be less accurate than same-race identifications. Cross-gender identifications exhibited the same disability, but the levels of inaccuracy were less significant.

Post-Offense Factors Post-offense factors also affect accuracy. Although the studies to date are somewhat inconclusive, longer delays between the offense and the identification procedure seem to produce fewer correct identifications and more false identifications. Most importantly, the studies have clearly shown the effects of commonly used police identification procedures. Researchers also suggest that several procedures not commonly used by police might produce more reliable identifications. For example, where witnesses first view a lineup without a suspect present and do not make any identification, subsequent lineups with the suspect present produce more accurate results. Researchers also urge the use of single-suspect lineups (when possible) with known-innocent distracters. The devastating effects of a mistaken identification choice are minimized by this procedure. The research on the effects of police procedure on eyewitness accuracy constitutes a broad sub-category of eyewitness identification studies. 8 However, several procedures and concepts warrant specific attention: "instruction bias," "sequential" and "simultaneous presentations," and "functional size."

"Instruction bias," the most obvious example of which involves the police telling the eyewitness that the suspect is present in the lineup or photo array, has a profound effect on false identification rates. Any suggestion by the police that a suspect is present in the lineup increases the number of positive identifications, and where police do not "instruct" the eyewitness one way or the other, the witness will fail to identify any suspect more frequently. Even where no instruction bias is present, the structure of the lineup procedure may affect the accuracy of identifications. Studies suggest that the cognitive process used by an eyewitness in selecting a person from a lineup involves a "relative judgment." This simply means that the eyewitness will choose the person who most resembles the eyewitness's memory of the offender relative to the other members of the lineup. Thus, in lineups where the actual culprit is absent, error rates will increase. To combat the effects of the relative judgment process, researchers have suggested use of "sequential presentation" procedures. In sequential identification procedures, the witness is presented with single photographs or given the opportunity to view each possible offender separately. In contrast, simultaneous lineups involve the presentation of all possibilities at once. The findings show that a simultaneous presentation -- which is used most often by police -- doesn't produce a higher number of correct identifications where the "offender" is present in the lineup, but it does produce more mistaken identifications where the "offender" is absent. Sequential procedures, on the other hand, produce fewer false identifications where the culprit is absent and do not reduce the number of accurate identifications where the culprit is present.

"Functional size" refers to the number of members of a lineup procedure who resemble the suspect closely enough to be a viable choice for the eyewitness. Functional size can be contrasted with "nominal size," which indicates the total number of members of a lineup. For example, if there are six members of a lineup or photo array, five of whom are black and one (the suspect) is white, the functional size is one, the nominal size six. The ability of the witness to identify the culprit is not significantly reduced by increases in functional size.

9 Defense Counsel's Options Although an expert witness could certainly help to explain the factors affecting eyewitness accuracy in a particular case, defense counsel typically must rely on the "protection" afforded by jury voir dire and instruction, and eyewitness cross-examination. However, counsel may not be afforded the opportunity to identify "favorable" jurors during voir dire, and studies also suggest that jurors' general attitudes toward eyewitnesses do not predict reactions to specific testimony with any degree of accuracy. Jurors tend to over-estimate the accuracy of eyewitness identifications: they undervalue the effects of viewing conditions and over-value the witness's memory of peripheral details and confidence in the identification choice. Regardless, defense counsel should request that the court read to the jury CJI2d 7.8, which alerts jurors to the inherent problems with eyewitness testimony. 10 Cross-examination of the eyewitness is limited by counsel's access to information about the viewing conditions at the crime scene, witness factors, and knowledge of the actual procedures used during subsequent police procedures. In addition, as noted above, the right to counsel during such police procedures may not apply, and when it does, the damage caused by the suggestive procedure may be imperceptible or simply too strong for defense counsel to overcome. When confronted with these problems, defense counsel must first gain a familiarity with the factors that influence eyewitness accuracy established in the recent studies. In particular, it may be useful for counsel to review the findings on the effects of weapon focus, changes in facial features and the use of "disguises," cross-race recognition, and, most importantly, the suggestiveness of commonly used identification procedures. The use of expert testimony on these factors can be very helpful.

Although the data on the effectiveness of expert testimony is necessarily limited because of the current state of the law, findings suggest that jurors are not confused or prejudiced by such testimony. It educates jurors, and this works for both the prosecution and defense. Moreover, unopposed expert testimony produces the greatest degree of juror sensitivity to the factors outlined above and the least amount of skepticism of the testimony.

11 Using Expert Testimony on Eyewitness Reliability The goal is to challenge jurors' mistaken confidence in the reliability of eyewitness testimony. To increase the likelihood that the expert testimony will be admitted, it is important to begin searching for the expert witness early so that he or she will have ample opportunity to become familiar with the facts of the case. The ability of the expert witness to testify to the connection between general principles established by the research and the operative psychological factors in the case at bar is crucial. Securing the Expert Witness The witness must be a qualified psychologist with sufficient "knowledge, skill, experience, training, or education" to meet the requirements of MRE 702. The witness must demonstrate that he or she is familiar enough with the facts of the case to aid the jury in understanding a material issue in the case. People v Boyd, 65 Mich App 11 (1975). The psychology department of a major university would be a good place to began searching for a qualified expert. Also, even a cursory examination of the scientific literature will provide counsel with several possible sources. The witness must know the methodology used in experiments on eyewitness identification. Prior experience testifying is also helpful. Expert-witness fees will vary according to the witness's credentials and experience. Indigent defendants may have a due-process right to a court-appointed expert if the testimony is crucial to the case. MCL 775.15; MRE 706. The defendant must show that he cannot proceed safely to trial without appointment of the expert, that a denial would result in an unfair trial. 12 This will generally not be the case where the defendant presents alibi witnesses. More importantly, the subject matter of the testimony must be proper. As noted above, the general principles in question must be applicable to the specific facts of the case in which the expert is to testify. Furthermore, in Michigan, the general principles underlying the proffered testimony must meet the "general acceptance" standard of Frye v United States, 54 USApp DC 46; 293 F 1013 (1921). This means that defense counsel must initially overcome the "bad science" hurdle. The issue is not whether all experts in the field agree, but whether the method of inquiry in the field is generally accepted as sound scientific methodology. This should no longer be the problem that it once was because the scientific basis of eyewitness-reliability experiments is generally accepted within the field. Defense counsel's familiarity with the studies will certainly help meet this requirement. 13 In addition to showing that the methodology underlying the proposed testimony is sound, defense counsel must show that the probative value of the evidence is not substantially outweighed by its likely prejudicial effect or the likelihood of juror confusion or waste of time. MRE 403. The inquiry will involve a balancing of two factors:

   1.the ability of the expert's testimony to aid the trier of fact to accurately determine a disputed issue or the likelihood of misleading or confusing the jurors, and 

   2.the "fit" between the subject matter of the proffered testimony and the particular factors involved in the case that may have impaired the accuracy of the eyewitness's identification of the accused. 

United States v Downing, 753 F2d 1224, 1227 (CA 3, 1985). People v Smith, 425 Mich 98 (1986). In showing that the probative value will not be outweighed by prejudice or juror confusion, defense counsel will have to overcome two commonly held assumptions: (1) jurors exaggerate the importance of expert testimony, and (2) the expert will testify to common-sense information and cross-examination of the eyewitness would produce essentially the same result as the expert testimony. To undermine these assumptions of prejudice and confusion, defense counsel may wish to argue that findings on several factors are far from unanimous: thus, the "common-sense" argument may not be persuasive in a given case. Most importantly, counsel must connect the expert's qualifications and the subject matter of the proffered testimony to specific factual issues in the case. Counsel should not simply argue factors affecting the eyewitness's immediate ability to perceive the offender. In addition, ask whether:

   1.the eyewitness is very young or old; 

   2.the delay between the offense and a subsequent identification procedure was lengthy; 

   3.the lineup or photo array was conducted using one of the fallible procedures identified above (instruction bias,simultaneous presentation, low functional size); 

   4.the identification is cross-racial or cross-gender; 

   5.the eyewitness displayed confidence in the identification choice or extensive recall of peripheral detail; 

   6.the suspect wore a hat or other "disguise;" 

   7.the suspect displayed a weapon. 

Then offer to the court the expert's work on the relevant factors and the findings of that and other researchers' work. When examining the expert, if possible given the facts of the case, stick to questions concerning the factors about which there is little debate. Again, "malleable" witness characteristics, offense characteristics, and the effects of police identification procedures are all areas upon which broad consensus within the psychology community exists. Avoid questions which invite the expert to comment directly on the reliability of the eyewitness in the case. The goal is simply to invite the trier of fact to question the assumption that eyewitness testimony is per se reliable and persuasive. If expert testimony on eyewitness identifications is allowed at trial, the jury will almost certainly make a better informed evaluation of the identification. If such testimony is more frequently admitted during criminal trials, it seems likely that fewer innocent persons will be convicted. by Tobin Miller, Research Assistant & principal author, and Fred Bell, Assistant Defender Both Mr. Miller and Mr. Bell work in the Lansing office of the State Appellate Defender Office.

                                        ENDNOTES 



   1.For a recent and complete summary of research findings, see Cutler & Penrod, Mistaken Identification: The Eyewitness, Psychology, and the Law (New York: Cambridge UP, 1995), pp 55-269. 2.Many of the studies are funded by such organizations as the National Science Foundation, the National Institutes  of Mental Health, and the National Institute of Justice. Studies are also subject to peer review. Thus, despite suspicion that psychologists do not engage in scientific research, it is clear that the methodology of the studies should withstand scrutiny under both the Frye and Daubert standards. 3.Also, the Kachar factors are broadly phrased whereas the experts' studies often precisely define the factor affecting eyewitness accuracy.  4.Shapiro & Penrod, Meta-Analysis of Facial Identification Studies, 100 Psychological Bulletin 139 (1986). This article summarizes 128 studies involving 16,590 subjects and is thus the most comprehensive review of eyewitness studies to date. Unfortunately, however, no studies on the effects of witness intoxication or "weapons focus" are included. 

5.It should be noted that, in some studies, the improvement in accuracy "levels off" as duration increases beyond a certain time. 6.Research on the effects of witness stress and arousal, and on the effects of violence, is necessarily limited because of ethical restraints on the researcher. Some studies utilizing videotaped exposure to violent crime do indicate a high correlation between violence, identification accuracy, and witness memory. As to witness arousal, the

"Yerkes-Dodson Law" holds that attentiveness levels correspond to levels of arousal in this way: a person just waking up has low arousal and low attentiveness; an athlete preparing for performance has moderate levels of arousal and an ideal level of attentiveness; a person in danger or under duress has high levels of arousal and low attentiveness.  7.Shapiro & Penrod, supra, at 145. See also, Anthony, Cooper & Mullen, Cross-Racial Facial Identification: A

Social Cognitive Integration, 18 Personality and Social Psychology Bulletin 296 (1992). 8.See Wells, What Do We Know about Eyewitness Identification? 48 American Psychologist 553 (1993) for information on the effects of police procedures on eyewitness accuracy. Wells, a well-known researcher of the topic, clearly defines key terms and provides a complete bibliography.  9.Lindsay & Wells, What Price Justice? Exploring the Relationship of Lineup Fairness to Identification Accuracy. 4 Law & Human Behavior 303 (1980). 10.This instruction reflects the general conclusions of Franklin Anderson, supra. 11.See Cutler, Dexter & Penrod, Expert Testimony and Jury Decision Making: An Empirical Analysis, 7 Behavioral

Sciences and Law 215 (1989). 12.See Ake v Oklahoma, 470 US 68 (1985) (capital case), and People v David Allen Carson, supra. 13 See Sheldon & MacLeod, From Normative to Positive Data: Expert Psychological Evidence Re-Examined, 1991

Crim L R 811 (1991).