The effect of surgical masks on identification decisions from masked and unmasked lineups

While research has shown that wearing a disguise hinders lineup identifications, less is known about how to conduct lineups in cases of disguised perpetrators. We examined the influence of surgical masks, worn during a crime event (encoding) and within lineups (retrieval), on eyewitness identification accuracy. In our experiment, 452 participants watched a mock-crime video and identified the perpetrator from either a target-present or a target-absent simultaneous lineup. Contrary to expectations based on the encoding specificity principle, we did not find that matching the presence of masks in the lineup to the encoding condition increased identification accuracy. Instead, compared to the condition with no masks at encoding and retrieval, the presence of masks at either stage negatively affected discriminability and undermined the predictive utility of confidence and decision time. Our findings indicate that when a witness has encountered a masked perpetrator, presenting them with a masked lineup may not be necessary.