Expert testimony on eyewitness evidence: in search of common sense.

Surveys on knowledge of eyewitness issues typically indicate that legal professionals and jurors alike can be insensitive to factors that are detrimental to eyewitness accuracy. One aim of the current research was to assess the extent to which judges, an under-represented sample in the extant literature, are aware of factors that may undermine the accuracy and reliability of eyewitness evidence (Study 1). We also sought to assess the knowledge of a jury-eligible sample of the general public (drawn from the same population as the judges) and compared responses from a multiple choice survey with a scenario-based, response-generation survey in order to investigate whether questionnaire format alters the accuracy of responses provided (Study 2). Overall, judges demonstrated a reasonable level of knowledge regarding general eyewitness memory issues. Further, the jury-eligible general public respondents completing a multiple choice format survey produced more responses consistent with experts than did participants who were required to generate their own responses. The results are discussed in terms of the future training requirements for legal professionals and the ability of jurors to apply the knowledge they have to the legal context.

The emotional eyewitness: the effects of emotion on specific aspects of eyewitness recall and recognition performance.

The present set of experiments aimed to investigate the effects of negative emotion on specific aspects of eyewitness recall and recognition performance. The experience of emotion was manipulated between subjects, with participants either viewing a crime scenario (a mugging) or a neutral scenario (a conversation). Eyewitness recall was categorized into descriptions of the perpetrator, critical incident, victim, and environmental details. The completeness and accuracy of eyewitness recall across categories of detail were measured in Experiment 1. A significant main effect of negative emotion was found for the completeness of recall. Furthermore, a significant main effect of the completeness of eyewitness statements was found, but not for their accuracy. However, these main effects were qualified by a significant interaction between emotion and category of detail recalled. Specifically, emotional participants provided a more complete description of the perpetrator than neutral participants; however, they were less able than their neutral counterparts to describe what the perpetrator did to the victim. In light of these findings, Experiment 2 investigated whether enhanced completeness of perpetrator descriptions during recall translated into an enhanced ability to recognize the perpetrator from a photographic lineup by emotional compared with neutral participants. Results from Experiment 2 suggest that while emotional participants again provide a more complete description of the perpetrator, they are less able than their neutral counterparts to recognize the perpetrator from a photographic lineup. Results are discussed in terms of a retrieval motivation hypothesis of negative emotional experience and the possible consequences for eyewitness testimony.