The Mystery Man Can Increase the Reliability of Eyewitness Identifications for Older Adult Witnesses

Some groups of eyewitnesses, such as older adults and children, are less likely to correctly reject a target-absent (TA) line-up, as compared to younger adults. Previous research reports that using a silhouette in a video line-up called the ‘mystery man’ could increase correct rejections for TA lineups for child eyewitnesses, without reducing correct identifications for target-present (TP) line-ups (Havard and Memon in Appl Cogn Psychol 27:50–59, 2013). The current study, using older and younger adults, investigated whether using the mystery man would also increase the identification accuracy for older adults, without impairing younger adults’ identification accuracy. The results found that older adults in the ‘mystery man’ condition rejected TA line-ups significantly more often than those in the control condition (52 vs. 24 %), with no significant effect upon the TP line-ups. For the younger adults, the mystery man had no influence on identification responses for the TA or TP line-ups. Our findings suggest the mystery man technique may be beneficial for older adults, without detrimentally affecting the accuracy for younger adults, and thus could increase the reliability of eyewitness evidence, where video line-ups are employed.