The impact of multiple show-ups on eyewitness decision-making and innocence risk.

Abstract

If an eyewitness rejects a show-up, police may respond by finding a new suspect and conducting a second show-up with the same eyewitness. Police may continue finding suspects and conducting show-ups until the eyewitness makes an identification (Study 1). Relatively low criterion-setting eyewitnesses filter themselves out of the multiple show-ups procedure by choosing the first suspect with whom they are presented (Studies 2 and 3). Accordingly, response bias was more stringent on the second show-up when compared with the first, but became no more stringent with additional show-ups. Despite this stringent shift in response bias, innocence risk increased with additional show-ups, as false alarms cumulate (Studies 2 and 3). Although unbiased show-up instructions decreased innocent suspect identifications, the numbers were still discouraging (Study 4). Given the high number of innocent suspects who would be mistakenly identified through the use of multiple show-up procedures, using such identifications as evidence of guilt is questionable. Although evidence of guilt is limited to identifications from a single show-up, practical constraints might sometimes require police to use additional show-ups. Accordingly, we propose a stronger partition between evidentiary and investigative procedures.

The Show-Up Identification Procedure: A Literature Review

“…Thus, it appears that the instructions given both before and after a potential identification can have a large impact on witnesses. In line with these findings, a recent study by Smith et al [3] had witnesses attempt identifications from show-ups with either unbiased instructions (e.g., it is just as important to clear innocent suspects as to identify the guilty perpetrator. The police investigation will continue even if you do not make an identification) or no unbiased instructions.…”

“…This is reflected in a survey of experts in the eyewitness area where only 74% of researchers believed the show-up procedure to be reliable enough for psychologists to present in court [10]. Despite the seemingly negative aspects of show-ups, Smith et al [3] have argued that show-ups have several positive features that make them important to further investigate. For example, show-ups can be created very quickly and is not nearly as time consuming as creating a lineup.…”

“…When police are presenting a show-up to a witness, two different results are possible [6]: the witness can make a correct identification or an incorrect rejection (if the show-up contains the perpetrator) or the witness can make a correct rejection or a false identification (if the show-up does not contain the perpetrator). This obviously makes the show-up procedure very suggestive since the identity of the suspect is known to the witness throughout the entire procedure [3]. Other scholars have also pointed out the suggestiveness of the show-up procedure.…”

“…Here witnesses are presented with only one photo or person and asked whether this person is the real perpetrator [2]. A recent study finds that show-ups are used by both American and Canadian police officers and that they are most common among the American police officers [3]. Thus, because the show-up procedure is frequently used, research about this identification procedure is warranted.…”

A Field Study Examining the Effect of High Intoxication Levels and Identification Format on Witnesses' Memory for Faces and Events

“…Despite these warnings, showup identifications are still admissible as evidence in court (Agricola, 2009;Cicchini & Easton, 2010). Furthermore, a majority of law enforcement agencies across the U.S support the use of showups (NIJ, 2013;Sjӧberg, 2016;Smith et al, 2014). This support stems from the fact that showups are easier to create than lineups and provide officers with a quick way to apprehend and/or eliminate a suspect from an investigation, especially when the suspect is apprehended within hours of the crime (Agricola, 2009;Cicchini & Easton, 2010).…”