THE EFFECTS OF DELAY ON THE PERFORMANCE OF COMPUTERIZED FEATURE SYSTEMS FOR IDENTIFYING SUSPECTS

In suspect identification, witnesses examine photos of known offenders in mugshot albums. The probability of correct identification deterior ates rapidly, however, as more photos are examined. Computerized featu re systems, which display mugshots in order of similarity to witness d escriptions increase success by reducing the number of mugshots examin ed. Previous experimental tests failed to examine the effects of delay (in eliciting witness descriptions) on recall memory and system perfo rmance, as well as the effects of number of raters per mugshot, and li ve target suspects (rather than using photos of men as targets). In tw o studies (one with live and one with photo target suspects), subject witnesses described targets after delays varying from several days up to four weeks. Delay had no effect on the number of photos examined, a lthough in the fourth week the accuracy of witness feature description s of suspects began to deteriorate. Two raters per mugshot significant ly improved performance. More raters did not improve performance furth er. Regardless of delay, witness searches resulted in photos of target suspects retrieved on average among the first 20-45 mugshots for a da tabase of 1000 mugshots before a target suspect's photo was displayed. The effects of delay on recall memory were similar to those reported previously for recognition memory of faces.