Police Lineups

If asked to describe a police lineup, most people would describe the NCIS version where the witness stands behind a glass, six suspects walk in, and the witness claims which number is the perpetrator or states that the perpetrator is not present. When the later happens, the investigator tells the witness to take her time and asks if she is positive and the drama continues. The reason this is the scene that people describe because this is the long-held protocol for police lineups. In the article “Police Lineups of the Future?”, Brewer et al. (2020) suggests that this traditional lineup continues to be the norm despite the large number of mistaken identifications throughout the United States. The researchers in this study are promoting a change to this traditional lineup that relies on the eyewitness’ confidence rating of each person in the lineup from 0% of absolutely not to 100% confident of being the perpetrator.

The researchers in this study set up laboratory observations of experimental police lineups as their descriptive method to determine the correlation between an eyewitness’ confidence level and the probability of guilt of the culprit. Of the six experiments, five used adult witnesses as participants and one used elementary students. Brewer et al. (2020) recruited a diverse group of participants by seeking the volunteers not only from the undergraduate student body but from the local community surrounding Flinders University in Australia. Median ages and gender ratios were taken into consideration when recruiting participants in order to mirror a typical population.

Brewer et al. (2020) experimental procedure mimicked a true lineup scenario as participants were required to watch four videos of a non-violent crime and then were placed in one of six experimental groups. The variances between the groups included whether the culprit was present in the lineup or not, the amount of time between the videos and being asked to identify the culprit from 12 lineup photos, and whether there was a deadline to the amount of time one had to respond to the photo (Brewer et al., 2020). Participants were simply asked to rate their confidence level of each suspect rather than selecting the culprit.

When the pressure of choosing the culprit was taken away, “the confidence procedure enables the witness to provide a sensitive index of the match between the suspect and memory, it provides useful probabilistic information about suspect guilt” (Brewer et al., 2020). Investigators would be able to compare whether a person of consideration is a strong or weak suspect from the eyewitness’ confidence score. As a result of this experiment, Brewer et al. (2020) suggest that suspects who are guilty will not be totally eliminated from the investigation because this method of providing a confidence ratio allows the eyewitness to trigger recognition memory.

An investigative team will have better leads with this confidence level information following a police lineup. The limitations to the experimental conclusions are that the theory will take much convincing of different faucets of our criminal justice system before it would be put into practice. In the future, courtroom lawyers may be arguing about the confidence level to prove their innocence of their client.

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