Eliciting person descriptions from eyewitnesses: A survey of police perceptions of eyewitness performance and reported use of interview techniques

摘要

Techniques such as the cognitive interview (CI) have the potential to improve witness recall. Nevertheless, there is also laboratory evidence of “verbal overshadowing”; the phenomenon whereby verbally describing aspects of an event (such as the face of a perpetrator) can have negative consequences for eyewitness memory. Seventy-two UK police officers were surveyed regarding their perceptions of eyewitness performance and the methods they use to elicit person descriptions from witnesses. Factors commonly believed to influence description quality were the viewing conditions of the event, the characteristics of the witness, and their mental distress. When eliciting person descriptions there was a consensus that some components of the CI were more frequently used and believed to be more useful than others. Witnesses were generally believed to provide accurate, but incomplete person descriptions. Nevertheless, there were instances where officers reported requesting elaborative face descriptions. We propose that verbal overshadowing is unlikely to be a major concern for most police officers; however, under some circumstances its potential impact should be considered. It is also clear that it would be of benefit for future research on verbal overshadowing to examine a number of variables relevant to the forensic setting.