Selecting lineup foils in eyewitness identification experiments: Experimental control and real-world simulation

Experimental research on eyewitness identification follows a standard principle of experimental design. Perpetrator-present and perpetrator-absent lineups are constructed with the same foils; so that the two conditions ave identical except for the presence or absence of the true perpetrator of the crime. However this aspect of the design simulates conditions that no nor correspond to those of real criminal investigations. Specifically, these conditions can create perp-absent lineups in which the foils are selected based on their similarity to an unknown person-the real perpetrator. Analysis of the similarity relations predicts that when foils for perp-absent lineups are selected based on their match to the perpetrator the false identification rate will be lower than if the foils are selected based on their match to the innocent suspect. This prediction was confirmed ire nit experiment that compared these two perp-absent lineup conditions These results suggest that false identification rates in previous experiments would have been higher if the foils had been selected based on their match to the innocent suspect, rather than the absent perpetrator.