Sequential lineups do not attenuate the biasing effect of tattoos

Abstract

Prior research has demonstrated that tattoos negatively affect identification accuracy in simultaneous lineups. However, research has not explored the effect of tattoos with sequential lineups. As sequential lineups have been shown to attenuate bias (Lindsay et al., 1991), I examined whether sequential presentation could mitigate the biasing effect of a tattoo. Participants completed eight trials; in each trial they watched a mock-crime video, viewed a biased or unbiased simultaneous or sequential lineup, and then rated their confidence in their decision. Sequential lineups did not reduce false identifications of tattooed suspects compared to simultaneous lineups, unfortunately. Thus, it is essential that the police follow current recommendations and ensure that all lineup members either appear with a tattoo or without a tattoo, as failing to do so increases the risk of wrongful convictions through an increase in false identifications. Exacerbating the effect, I found that participants expressed significantly higher confidence in false identifications when the lineup was biased compared to unbiased. As confidence is the primary predictor of judgments of the credibility of eyewitness evidence, this result further highlights the need for police to present eyewitnesses unbiased lineups.