§ 10.02. Eyewitness Identification Procedures

Police agencies should adopt standard, written eyewitness identification procedures to regulate the use of showups, lineups, photo arrays, and any other eyewitness identification techniques they employ, whether in the field or the station. Agencies should ensure that the specific procedures they use to test the memory of an eyewitness are informed by extant research. Those procedures should include:

  • (a) direction to conduct any identification as early as possible in the course of an investigation;
  • (b) instructions to explain the procedure to the eyewitness in easily understood terms;
  • (c) procedures for fairly selecting non-suspect or “filler” persons or images to display to the eyewitness;
  • (d) procedures for presenting persons or images to the eyewitness in a nonsuggestive manner;
  • (e) procedures for documenting any identification or nonidentification by the eyewitness; and
  • (f) procedures that employ sequential or simultaneous presentation of photos in photo lineups.


a. Written policy. Traditionally, eyewitness identification procedures were not governed by written police policies. Rather, this was the type of task that officers would learn informally and on the job. Agencies did not have standardized instructions or procedures. Some agencies still do not have written eyewitness identification policies, and that problem remains a pressing one. This Section sets out each of the key elements of identification procedures, based on current scientific research. This Section also indicates areas that still are the subject of disagreement and ongoing research in the scientific community, such as presentation of photographs sequentially rather than simultaneously.

b. Timing. The memory of an eyewitness degrades over time. It is crucial that officers conduct eyewitness identification procedures as promptly as possible.

c. Procedures. The procedures for conducting an eyewitness identification should be clear and easily understood by witnesses. Standard procedures will ensure uniformity and avoid any misunderstanding by, or suggestion to, the eyewitness, even if inadvertent. It is important, for example, to convey that the culprit may or may not be present, because a witness may assume they have been asked to identify the culprit. Procedures should also be blind or blinded, as stated in § 10.05. The confidence of an eyewitness should be recorded, and the entire procedure should be recorded, as stated in § 10.08.

d. Fillers. The more fillers presented in an eyewitness identification procedure, the more reliable a test of the eyewitness’s memory the procedure is. Typical rules require that five fillers be presented along with a suspect. Some agencies require that six or more be included, which provides a still more rigorous test. It is also permissible that, among the individuals or photographs included in a lineup, none is a suspect.

An unfair or biased lineup, in which the suspect stands out, can lead to errors. Rules should clearly set out how to select fillers. Such rules should require that police, after obtaining a description from the eyewitness, should select fillers who each fairly reflect the eyewitness’s description of the suspect. The fillers should not make the suspect stand out in a manner that is suggestive. It may be necessary, for example, to mask a portion of the fillers’ faces, if the suspect has a tattoo that the fillers would lack.

Only a single suspect should be present in any given lineup procedure. If there is more than one suspect, then additional and separate lineup procedures should be conducted for each additional suspect.

e. Documenting identifications. Eyewitness identification procedures should be documented, preferably by use of a video and audio recording, unless exigent circumstances make doing so impossible. Procedures should also be developed to mask the identity of eyewitnesses appearing in a recording, when there are investigative needs to do so. It is important that the procedure be documented, with the statements and identification decisions by the eyewitness written down. It is important to contemporaneously document the confidence of the eyewitness, because that confidence may change quite a bit based on feedback after the lineup.

f. Uniform policy and training. It is also important that agencies use standard eyewitness identification procedures, including with clear, written policies and training on their administration. The modern approach, treating eyewitness identifications as an experiment and a test of human memory, depends upon standard protocols and procedures. Absent consistent and clear procedures, there can be no uniformity or consistency of results, and eyewitnesses may themselves be confused or misled during an eyewitness identification procedure. As with all areas of agency policy, written policy must be implemented through sound training and supervision, not just in the academy, but in service. Supervision should include discipline for officers who fail to adhere to written policy and training on eyewitness identification procedures. Such supervision and training is important not just for officers who routinely conduct lineups, but for all officers who conduct investigations relying on eyewitness memory. For example, an officer’s field interview with an eyewitness, designed to elicit a description of a possible suspect, can play a crucial role in any subsequent identification procedures.

g. Right to counsel. Based on U.S. Supreme Court rulings interpreting the U.S. Constitution, defendants have a right to have counsel present at in-person lineups after an indictment, but they do not have a right to counsel at photo arrays, which are the most common method employed for eyewitness identification procedures. United States v. Wade, 388 U.S. 218, 228 (1967); United States v. Ash, 413 U.S. 300, 321 (1973). Nevertheless, police should notify counsel and permit counsel to be present during any identification procedures, in order to ensure the fairness of the procedures and to permit independent observation of the procedures.

h. Research on “sequential” or “simultaneous” is not decisive. There is a choice whether to present photos simultaneously (all at the same time) or sequentially (one at a time), and research on this issue at present is inconclusive. Many policing agencies view the sequential lineup as the more conservative option, because evidence suggests that it can prevent additional “comparison shopping” among images. Studies show that sequential lineups do reduce false identifications. Police more concerned with the cost of false identifications may choose that option. Sequential lineups also may reduce correct identifications. Some recent research suggests that for many eyewitnesses, the choice of procedure does not significantly impact results. Still, there is a live scientific debate about which type of presentation of images is the most accurate.

i. Written policy on presentation of photographs. Agencies should adopt a policy regarding the question of whether to conduct sequential or simultaneous presentation methods during eyewitness identification procedures, and should not leave this decision to the discretion of officers. In practice, some eyewitnesses may ask to view a sequential lineup a second time, which agencies commonly refer to as a second “lap.” If permitted to do so, a sequential procedure is in effect much like a simultaneous one. As a result, the differences between the procedures may not turn out to be crucial in practice. In any event, the choice of which type of procedure to use, sequential or simultaneous, cannot be fully answered based on the scientific research, and thus requires a considered policy decision by the agency.

Reporters’ Notes

Traditionally, many agencies did not have formal policies or practices concerning eyewitness identification procedures. Often any training that was conducted was highly informal. Michael S. Wogalter, Roy S. Malpass & Dawn E. McQuiston, A National Survey of U.S. Police on Preparation and Conduct of Identification Lineups, 10 Psychol., Crime & L. 69 (2004) (survey of 220 agencies finding that over half reported no “formal training” on eyewitness identification procedures). Surveys indicate that many law-enforcement agencies continue to lack written policies on the subject of eyewitness identifications; other agencies adopt written policies, but ones that do not comport with best practices. See, e.g., Police Executive Research Forum, A National Survey of Eyewitness Identification Procedures in Law Enforcement Agencies 46-47 (2013), at http://‌police‌forum.org/‌library/eyewitness-identification/NIJEyewitnessReport.pdf (reporting in a national survey of over 600 agencies that 77 percent lacked written policy for showups and 64 percent reported no written policy for lineups or photo arrays); Brandon L. Garrett, Eyewitness Identifications and Police Practices in Virginia, 3 Va. J. of Crim. L. 1 (2014) (study of Virginia law-enforcement policies, of which few complied with state model policy on lineup procedures); but see Brandon L. Garrett, Self-Policing: Dissemination and Adoption of Police Eyewitness Policies in Virginia, 105 Va. L. Rev. Online 101 (2019) (describing, five years later, widespread adoption of state model policy). Without standard policies and procedures, it can be far more difficult to assess what happened during an eyewitness identification procedure. Moreover, it is difficult to ensure standard quality of the identifications if no standardized protocols are observed.

The National Academy of Sciences Committee Report made quite clear its recommendation that blind or blinded lineups be used by law enforcement. Nat’l Research Council of the Nat’l Acads., Identifying the Culprit: Assessing Eyewitness Identification 3 (2014). Section 10.05 develops the importance of conducting lineups in that fashion. See also 2019 Report of the Third Circuit Task Force on Eyewitness Identifications 14 (2019).

Policies should explain how to select “filler” photographs that fairly resemble the description of the suspect and the suspect, so that the suspect does not stand out in the photo array. Resources should be made available to police agencies so that they have access to archives of photographs and are then able to have a sufficiently wide selection of photographs for use in photo arrays. A move toward computerized selection of photographs and administration of photo arrays may improve the fairness of the photographs selected. In addition, policies should discourage the use of multiple viewings, which can raise the risk of error. See State v. Henderson, 27 A.3d 872, 900-901 (N.J. 2011) (stating that “law enforcement officials should attempt to shield witnesses from viewing suspects or fillers more than once.”); see also 2019 Report of the Third Circuit Task Force on Eyewitness Identifications 14 (2019).

Agencies should adopt standard instructions for eyewitnesses. Those instructions should inform the eyewitness that a culprit may or may not be present in the lineup. See NRC, Identifying the Culprit, supra, at 107. That instruction is crucial because an eyewitness otherwise may expect that the culprit will be present and that there is a correct choice that should be made. As discussed in § 10.04, showups should be limited in their use. Such an instruction can still be given before conducting a showup, and agencies should have standard instructions and procedures to avoid undue suggestion in showup procedures. See NRC, Identifying the Culprit, supra, at 108. As discussed in § 10.08, the confidence of the eyewitness should be documented, preferably through a recording of the entire eyewitness identification procedure.

Standard procedures should use terminology that is easily understandable by eyewitnesses. See NRC, Identifying the Culprit, supra, at 107; 2019 Report of the Third Circuit Task Force on Eyewitness Identifications 15-16 (2019). There are a number of state statutes and model policies that provide useful models for agencies. See, e.g., N.C. Gen. Stat. § 15A-284.52 (West 2007); Ohio Rev. Code Ann. § 2933.83 (West 2010); The Commission On Accreditation For Law Enforcement Agencies, Inc., CALEA Standards For Law Enforcement Agencies: 42.2.11 Line-Ups, International Association of Chiefs of Police, Model Policy: Eyewitness Identification (2010), at http://www.theiacp.org/PublicationsGuides/ModelPolicy/ModelPolicyList/‌tabid/‌487‌/‌Default‌.aspx; Virginia Department of Criminal Justice Services, Model Policy on Lineups/‌Eyewitness Identification 2-39 (2013). In addition, police should make routine accommodation in policy and in practice for non-English speakers or others requiring accommodation, due to hearing or linguistic impairment or other disability. See NRC, Identifying the Culprit, supra, at 107. A move to computerized presentation of images can similarly ensure that clear, standard instructions and procedures are consistently used.

We note that while voice, or “earwitness” identification procedures are not the focus of these Principles, the same types of procedures should be adopted when a voice identification is conducted. Agencies should develop clear and consistent written procedures for presentation of voices to a witness, as well as fairly selected “filler” voices.

Many jurisdictions have adopted all or some portions of these recommendations. To date, 22 states have adopted legislation regarding eyewitness identification procedures. Of those, 17 states (California, Colorado, Connecticut, Florida, Georgia, Illinois, Kansas, Louisiana, Maryland, Nebraska, Nevada, New Hampshire, North Carolina, Ohio, Oklahoma, Texas, Utah, Vermont, Virginia, West Virginia, and Wisconsin) have enacted statutes directly requiring that law-enforcement officials adopt written procedures for eyewitness identifications. Some of those states regulate the particular procedures to be used, focusing on the key features of a sound policy as outlined above, including blind or blinded lineups, clear written instructions, and documenting the confidence of an eyewitness. See Cal. Pen. Code § 859.7 (2018); Co. Rev. Stat. § 16-1-109 (2016); Conn. Gen. Stat. § 54-1p (West 2012); Fla. Code Ann. § 92.70 (West 2017); Ga. Code Ann. § 17-20-2 (West 2016); 725 Ill. Comp. Stat. § 5/107A-5 (West 2003); Kansas SB 428 (2016); La. Code Crim. Pro. 251-253 (2018); Md. Code Ann., Pub. Safety § 3-506 (West 2007); N.C. Gen. Stat. § 15A-284.52 (West 2007); Neb. R.S. § 81-1455 (2016); N.R.S. 171.1237 (2011); N.H. R.S.A. Ch. 595-C (2018); Ohio Rev. Code Ann. § 2933.83 (West 2010); OK. S.B. 798 (2019); Tex. Code Crim. Proc. Ann. art. 38.20 (West 2011); Utah Code Ann. § 77-8-4 (West 1980); Va. Code Ann. § 19.2-390.02 (West 2005); Va. Code Ann. § 9.1-102.54; 13 V.S.A. § 5581; W. Va. Code Ann. § 62-1E-1 (West 2013); Wis. Stat. § 175.50 (West 2005). Additional states (Nevada and Rhode Island) have passed statutes recommending further study, tasking a group with developing best practices, or requiring some form of written policy. Nev. Rev. Stat. § 171.1237 (West 2011); R.I. Gen. Laws § 12-1-16 (West 2012); 2010 Leg. Reg. Sess. (Vt. 2010).

Many other jurisdictions have adopted model policies, and still others have had legislation introduced and considered on this subject. Several state courts have also issued rulings regulating lineup practices (e.g., New Jersey’s Supreme Court has required documentation of identification procedures). State v. Delgado, 902 A.2d 888 (2006). Many more jurisdictions and departments also have voluntarily adopted guidelines or policies regulating eyewitness identifications. See, e.g., John J. Farmer, Jr., Attorney General of the State of New Jersey, “Letter to All County Prosecutors: Attorney General Guidelines for Preparing and Conducting Photo and Live Lineup Identification Procedures” (April 18, 2001), available athttp://www.state.nj.us/lps/dcj/agguide/photoid.pdf; CALEA Standards for Law Enforcement Agencies: 42.2.11 Lineups, at http://www.calea.org/‌content/‌‌standards-titles; International Association of Chiefs of Police, Model Policy: Eyewitness Identification (2010).

Traditionally, agencies used simultaneous eyewitness identification procedures, whether those procedures were live or involved photographs. The move to photo arrays made it far more feasible to present images one at a time. Research had suggested that sequential presentations eliminated “comparison shopping” by eyewitnesses who would scan across images to locate the one most similar to their recollection. Many agencies, concerned with preventing wrongful convictions, switched to sequential presentation of images in photo-array procedures. However, more recent research suggests that the differences between the procedures are harder to assess and that it is not a straightforward choice. See NRC, Identifying the Culprit, supra, at 117. More research is needed on this question.

For a detailed discussion of the current research on this question and the ongoing debate in the scientific community over the preferable approach, see NRC, Identifying the Culprit, supra, at 117-118; see also, e.g., Nancy Steblay et al., Eyewitness Accuracy Rates in Sequential and Simultaneous Lineup Presentations: A Meta-Analytic Comparison, 25 Law & Hum. Behav. 457, 459-460, 462-464, 468 (2001) (recommending use of the sequential procedure to reduce use of “relative judgment”); Laura Mickes et al., Receiver Operating Characteristic Analysis of Eyewitness Memory: Comparing the Diagnostic Accuracy of Simultaneous Versus Sequential Lineups, 18 J. Experimental Psychol. Applied 361, 374-375 (2012) (recommending further empirical research).

In sum, scientists have increasingly questioned how great the difference is between simultaneous and sequential procedures. There is some evidence that the sequential procedure is the more conservative approach, particularly in terms of reducing false identifications. At the same time, it may reduce the number of correct identifications. The practical difference between the two procedures may be particularly small when agencies typically permit a witness to take a “second lap” and look at a sequential series of photos again. Selecting the right approach requires a policy choice by the policing agency, considering research but also practical considerations. See NRC, Identifying the Culprit, supra, at 119.

This question whether to adopt a sequential or simultaneous procedure highlights that, as in any scientific area, research continues to advance. Agencies, understandably, cannot revise their policies as quickly as science advances. One advantage of computerized presentations of images to eyewitnesses is that the program can readily be changed to adjust presentation methods. Funds should be made available for development and implementation of convenient computerized presentations, such as tablet-based eyewitness identifications.

Agencies should proceed cautiously regarding this topic of sequential versus simultaneous presentation. However, this scientific debate is a sign of engagement and hard work by researchers. It should not be taken as a reason not to adopt important protections, such as blind or blinded procedures, clear instructions, or recording, all of which have been endorsed by consensus in the scientific community.

Table of Contents