Eyewitness identifcations: Key or peril for police investigations?

Every year, thousands of identifications take place across Europe, with eyewitnesses playing a crucial role in the prosecution and conviction of suspects. However, even sincere witnesses can confidently identify the wrong person. Illustrated by a real-life example, we describe factors that play a role when a witness is asked to identify a perpetrator from a lineup. We show that testing eyewitnesses' memory for a perpetrator using a lineup only makes sense if they paid sufficient attention to the perpetrator under reasonably good viewing conditions and not only briefly, in the dark, or from a distance. Other factors, such as a cross-race identification, younger or older age, and alcohol intoxication can also have a negative effect on identification performance. For the reliability of the identification decision, it is crucial to ensure a fair lineup composition. Those who construct the lineup should consider the witness' perpetrator description and the similarity between foils and suspect, and test the appropriateness of the foils before administering a lineup. We also show how the behavior and instructions given by the lineup administrator can have devastating consequences. We close this chapter by emphasizing the importance of measuring witnesses' decision time and recording their confidence immediately after their identification decision. Understanding all of these factors and addressing them in guidelines for lineup construction and administration and in practice can improve the reliability of eyewitness identifications and help reduce the risk of wrongful convictions.