Recommended Eyewitness Procedures
Scientific Review Paper (Wells et al. 2020)
In "Policy and Procedure Recommendations for the Collection and Preservation of Eyewitness Identification Evidence", Wells et al. (2020), outline the best practices for collecting and documenting eyewitness identification evidence to minimize potential mistakes that can result in wrongful convictions. The American Psychology-Law Society appointed world-leading eyewitness researchers to create this Scientific Review Paper. All the recommendations are based on scientific evidence which supports the proposed policies and procedures.
Before conducting an identification procedure, officers should interview witnesses as soon as possible after the crime, documenting their descriptions of the culprit, viewing conditions, attention during the crime, prior familiarity with the culprit, and instruct them to not discuss the event with other witnesses and not to attempt to identify the culprit on their own. The entire interview should be video-recorded.
Before including someone in an identification procedure for a specific crime, there should be evidence-based reasons to suspect that they are guilty, and this evidence should be documented in writing prior to the lineup.
Double-Blind (or Equivalent)
Lineups should be conducted using a double-blind procedure, where neither the administrator nor the witness knows who the suspect is in the lineup, or another equally effective method to prevent the administrator from unintentionally influencing the witness.
Lineups should have only one suspect and at least five appropriate fillers, who do not make the suspect stand out based on physical appearance, clothing, or background.
When inviting an eyewitness to attend a lineup procedure, the police should not provide any new information and should not suggest that the suspect who will be in the lineup has been arrested or that the culprit will be present. The eyewitness should be instructed that the lineup administrator does not know which person is the suspect, the culprit might not be in the lineup, and they have the option of responding "don't know." After making a decision, the eyewitness should be asked to state how confident they are in that decision, and the investigation will continue even if no identification is made.
Immediate Confidence Statement
As soon as a witness makes an identification decision, whether positive or negative, they should be asked to provide a statement of confidence.
All aspects of the identification procedure, including prelineup instructions and witness statements of confidence, should be recorded on video.
Avoid Repeated Identifications
Avoid conducting a second identification procedure with the same suspect and eyewitness, whether or not the suspect was identified in the initial procedure.
Whenever possible, a lineup should be conducted instead of a showup. If a showup is necessary, it should include the procedural safeguards recommended for lineups, such as the removal of suggestive cues, a warning that the detained person may not be the culprit, video recording the procedure, and obtaining a confidence statement.