Testing Facial Composite Construction under Witness Stress

Facial composite systems may be used by police to help a witness to a crime create a likeness of the perpetrator. Evaluation of new facial composite systems in the laboratory allows a measure of experimental control, but lacks the emotional impact of a real crime. As a step towards a more realistic level of stress for our participant witnesses, we presented target face images while they were engaged in playing an action thriller computer game. The quality of the composites they subsequently produced was compared with that of a second ‘onlooker’ participant, who merely observed the game and had the same view of the target face. Heart rate monitoring confirmed that the players were more stressed than the onlookers while the recognition rate of the onlooker composites was twice as good. We conclude that the method holds some promise as a method for composite system evaluation.