Some groups of eyewitnesses, such as older adults and children, are less likely to correctly reject a target absent (TA) lineup, as compared to younger adults. Previous research reports that using a silhouette in a video lineup called 'the mystery man' could increase correct rejections for TA lineups for child eyewitnesses, without reducing correct identifications for target present (TP) lineups (Havard & Memon, 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 lineups. 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 lineups are employed.