NCJ Number
46457
Journal
Journal of Police Science and Administration Volume: 6 Issue: 1 Dated: (MARCH 1978) Pages: 35-42
Date Published
1978
Length
9 pages
Annotation
TWO EXPERIMENTS WERE UNDERTAKEN TO EXAMINE THE EFFECTS OF DELAY ON PHOTOFIT FACE CONSTRUCTION PERFORMANCE AND RECOGNITION ACCURACY.
Abstract
PHOTOFIT IS IN WIDESPREAD USE AS A TOOL FOR RECONSTRUCTING THE FACIAL APPEARANCE OF SUSPECTED OFFENDERS. THE KIT IS COMPOSED OF NUMEROUS PHOTOGRAPHS OF VARIANTS OF FIVE BASIC FEATURES: FOREHEAD AND HAIR, EYES AND EYEBROWS, MOUTH AND LIPS, NOSE, AND CHIN AND CHEEKS. IN EXPERIMENT 1, A GROUP OF HOUSEWIVES WERE PRESENTED WITH PHOTOGRAPHS OF TWO MALE STIMULUS SUSPECTS, ONE FOR IMMEDIATE PHOTOFIT CONSTRUCTION AND ONE FOR CONSTRUCTION ONE WEEK AFTER PRESENTATION. SCORING WAS BASED ON THE DEGREE OF PHOTOFIT CONSTRUCTION LIKENESS TO THE STIMULUS FACE AS JUDGED BY 20 VOLUNTEERS, THE ACCURACY WITH WHICH A FURTHER GROUP OF 20 JUDGES COULD SORT THE CONSTRUCTIONS INTO 2 GROUPS CORRESPONDING TO THE 2 STIMULUS FACES, AND THE ACCURACY WITH WHICH INDIVIDUAL JUDGES AND GROUPS OF 4 JUDGES COULD IDENTIFY THE STIMULUS FACE IN A GROUP OF 20 FACES ON THE BASIS OF THE PHOTOFIT CONSTRUCTION. REGARDLESS OF THE MEASURE OF PERFORMANCE EMPLOYED, THERE WAS NO DETECTABLE DECREASE IN RECONSTRUCTIVE ACCURACY OVER TIME. THIS DOES NOT HOWEVER NECESSARILY INDICATE THAT THERE IS NO REAL DECLINE IN DETAILED MEMORY OF FACIAL FEATURES OVER TIME. SUCH LOSSES MAY BE PRESENT BUT MAY NOT BE REGISTERED DUE TO THE INSENSITIVITY OF THE MEASUREMENT INSTRUMENT. SOME SUPPORT FOR THIS POSSIBILITY IS SEEN IN THE SUBSTANTIAL MINORITY OF PHOTOFIT CONSTRUCTIONS WHICH WERE UNRECOGNIZABLE AS THE TARGET AND THE LOW RATES OF IDENTIFICATION FOUND FOR ONE OF THE TWO STIMULUS FACES. EXPERIMENT 2 REPLICATED THE MAIN FEATURES OF THE FIRST EXPERIMENT, WITH THE ADDITION OF AN INDEPENDENT MEASURE OF STATE OF THE SUBJECT'S RECOGNITION MEMORY OF THE STIMULUS FACE UNDER BOTH THE IMMEDIATE AND DELAYED RECONSTRUCTION CONDITIONS. THE TIME OF DELAY WAS EXTENDED FROM 1 TO 3 WEEKS. ANALYSIS OF DATA INDICATED, AS IN EXPERIMENT 1, THAT PHOTOFIT ACCURACY IS NOT AFFECTED BY A DELAY INTERVAL: AS MANY HIGHLY RATED LIKENESSES WERE FOUND AFTER A THREE WEEK INTERVAL AS AFTER A DELAY OF ONLY A FEW HOURS. HOWEVER, SUBJECTS ATTEMPTING TO RECOGNIZE THE STIMULUS FACE DID SHOW A SIGNIFICANT DROP IN ACCURACY OVER THE DELAY INTERVAL. THIS SUGGESTS THAT PHOTOFIT INSENSITIVITY TO THE EFFECTS OF DELAY DOES NOT REFLECT A UNIQUE IMMUNITY OF FACIAL IMAGES TO TEMPORAL DEGRADATION, BUT RATHER INDICATES THE INABILITY OF THE TOOL TO TRANSLATE IMAGE INTO CONCRETE REPRESENTATION; E.G., FLUCTUATIONS IN MEMORY TRACE STRENGTH ARE UNLIKELY TO BE REFLECTED BY THE PHOTOFIT CONSTRUCTION. FINDINGS SUGGEST THAT THE UTILITY OF THE PHOTOFIT APPROACH TO SUSPECT IDENTIFICATION SEEMS DEPENDENT ON THE CONSTRUCTIVE SKILLS OF THE WITNESS AND A SUSPECT WHOSE FEATURES LEND THEMSELVES TO MODELING BY THE SYSTEM. (JAP)