In suspect identification, witnesses examine photographs of known offe
nders in mug-shot albums. The probability of correct identification de
teriorates rapidly, however, as the number of mug-shots examined incre
ases. Feature approaches, where mug-shots are displayed in order of si
milarity to a witness's description of a suspect, attempt to increase
identification success by reducing this number. A methodology is propo
sed for the design, development, and evaluation of these systems based
on computer simulations, experiments, and four classes of system perf
ormance measures: identification performance, retrieval rank, toleranc
e performance, and feature quality. This approach was used to develop
a suspect identification system for 640 mug-shots of known offenders.
System performance was good. In three experimental tests, > 90% of all
witness searches resulted in target suspects retrieved in the first e
ight mug-shots. The system is highly tolerant of witness errors and om
issions.