Forensic DNA testing has freed hundreds of innocent people in the U.S. and approximately 75% of these convictions involved mistaken eyewitness identification. The need to identify reliable ways to sort between accurate and mistaken identifications is readily apparent. Theory and data from laboratory-simulation experiments indicate that accurate and mistaken identifications differ in measurable ways (e.g., identification speed, confidence, witness verbalizations). Lab research also shows that lineup biases (e.g., innocent suspect stands out or administrator unintentionally steers the witness) can inflate mistaken identifications. Lab simulation participants, however, know that the crime is not real and fail to capture potentially important dynamics of actual witnesses (e.g., fear, justice motivations, concern for consequences).
The researchers have unique materials from actual cases involving 855 photo-lineups where only one person in each lineup was a suspect. The other lineup members were known-innocent fillers. Filler identifications, which constitute mistaken identifications, comprise 34% of all identifications. Software provided by the researchers made audio recordings of witnesses' verbalizations, speed of identifications, and other relevant information for each lineup. A majority of the lineups were administered double-blind; thus, lineup administrators were unaware of which was the suspect's photo and hence could not steer the witness. Four studies were conducted. Study 1 tests whether lineup bias predicts mistaken identifications. Study 2 tests whether witness verbalizations predict mistakes. Study 3 tests whether mistakes are slower and made with less certainty than suspect identifications. Study 4 tests whether double-blind lineup procedures evidence less steering by the lineup administrators. Data analyses involve hierarchical, mixed model log-linear analyses or ANOVAs. This work can help translate lab simulation findings to actual cases and thereby help the justice system sort between mistaken and accurate identifications. Results will be shared broadly with scientists, police and prosecutors. Undergraduate students, including first-generation and those of color at a small undergraduate college, will receive research training in this project.
