How effective is the motion-to-suppress safeguard? Judges' perceptions of the suggestiveness and fairness of biased lineup procedures.

The motion-to-suppress safeguard is designed to prevent false eyewitness identifications from leading to wrongful convictions. This safeguard is effective only if judges are sensitive to factors that influence lineup suggestiveness. The present study assessed judge sensitivity to foil, instruction, and presentation biases. Judges (N = 99) read a description of a hypothetical crime, perpetrator, and identification procedure followed by a motion to suppress the identification. Judges completed a questionnaire in which they ruled on the motion and rated the lineup's suggestiveness and fairness. Foil bias and instruction bias influenced judges' rulings and lineup evaluations as predicted. Hypotheses concerning presentation bias were not supported. These results suggest that judges are somewhat sensitive to lineup suggestiveness but there is room for improvement.