The delayed impact of informed versus blind interviewing on eyewitness memory

Abstract Background Previous research has highlighted the potentially detrimental effects of pre‐interview preparation on witness memory within an interview context (Rivard et al., 2016). The present study examined the effect of an interviewer's pre‐interview knowledge on eyewitness memory beyond the initial interview. Method Student witnesses were interviewed one week after viewing a mock crime event by a student interviewer who was either correctly informed, incorrectly informed, or uninformed (blind) to case details and who was either told to avoid suggestions or was not given cautionary instructions. Results Analyses of the witnesses' recall quantity and quality one week after the interview revealed that witnesses of blind interviewers recalled more details than witnesses of incorrectly informed interviewers. Witnesses of blind interviewers were also more accurate than witnesses of incorrectly informed interviewers, but only when interviewers were warned not to ask suggestive questions. Implications Findings suggest that interviewer training and pre‐interview knowledge may play an important role in witness recall.