Southeastern Louisiana University researchers exploring the computerized multimedia mug book found that a dynamic procedure of reviewing mug shots improved identification performance over that of the traditional procedure (J Applied Psychology 1997, Vol. 82, No.5, 688-698). In addition, allowing witnesses the choice of presentation of dynamic information improved performance over that of a dynamic mug book where no such choice was allowed.
The use of computers to improve eyewitness performance in viewing mug shots has taken advantage of current computers' capability to store massive amounts of information and to sort quickly and retrieve stored information; however, the multimedia capabilities of current generation microcomputers has yet to be utilized.
A total of 286 introductory psychology students participated in the study. By using video clips, the witness could hear the mug book members' voices, see them in motion, see their full body, and see them from every possible angle. Two slightly different 5-mm color videotapes of three actors playing a crime scene were shown to 150 and 136 subjects, respectively. Color video film clips had been made of 72 foils with no attempt to match them to the perpetrator. The foils' speech samples were 10 seconds. They turned 360 degrees on a stool for 10 seconds, and they walked a triangular path for 10 seconds. Mug shot stills were created for the foils and the crime scene actors.
Three different conditions were tested. All three began with a static mug shot picture of the first individual in the file, accompanied by the question, "Was this the person who committed the computer crime?"; then, "How confident are you of your answer?" In the first, or static, condition, the computer then went to the next static picture. In the second, or dynamic no-choice condition, the computer presented the 30-second video clip after the static shot, asked the same two questions, then went to the next static picture. The third, or dynamic choice, condition, depended on participants answering yes to the question, "Would you like additional information?" Then the computer presented the dynamic clip followed by the two questions just as in the other two conditions. Good correspondence existed between the perpetrator's voice and gait in the crime scene and those in the mug book. In certain crimes, however, correspondence might not be so close.
Not a single circumstance existed in which there was superior performance in the static mug book as compared with the dynamic conditions. The dynamic choke procedure was superior to the dynamic no-choice condition on all final performance measures, and with only a modest increase in the time to conduct the search over using the static mug books. Of significance to the criminal court, the impact of the dynamic information was greater in reducing false positives than in increasing correct identifications. Thus, dynamic mug book technology has considerable promise.
