Eyewitness testimony is critically important to the justice system. Indeed, it is necessary in all criminal trials to reconstruct facts from past events, and eyewitnesses are commonly very important to this effort. Psychological scientists, however, have challenged many of the assumptions of the legal system and the general public regarding the accuracy of eyewitness accounts. Particularly dominant in the psychological science literature are the views that memory reports are malleable (i.e., changed by suggestive questioning), that witnesses can be made to be extremely confident in inaccurate memories, and that police lineups should follow a careful protocol in order to avoid high rates of mistaken identification. The principal methods used by psychological scientists for examining the accuracy of eyewitnesses involve creating events that unsuspecting people witness and then collecting their reports about what they saw. Because the events were created by the researchers, these reports can be scored for their accuracy and completeness. In this way, researchers can systematically manipulate various factors (such as stress, view, the use of misleading questions, the instructions given prior to a lineup) to determine what variables influence accuracy and completeness. This body of research has its programmatic origins in the mid- to late 1970s, but it received a large boost to its credibility in the 1990s, when forensic DNA testing began to uncover convictions of innocent people. Over 75 percent of these exonerations are cases involving mistaken eyewitness identification. The discovery of these mistaken identifications and resulting wrongful convictions has been a jarring event for the legal system and threatens public faith in the criminal justice system. Accordingly, eyewitness research today is having a larger impact on the legal system as the legal system recognizes that eyewitness errors are leading to faulty trial outcomes. The scientific literature on eyewitness testimony that has emerged is an important development in showing the relevance of social science for helping to solve problems in the legal system. An increased use of eyewitness experts at trial and revisions to how eyewitnesses are interviewed and how lineups are conducted represent concrete legal system improvements resulting from this line of research.

Eyewitness Testimony
Adele Quigley-Mcbride. Laura Smalarz, Gary Wells.
Oxford, 2018