TY - JOUR
T1 - Detection of Guilty Knowledge in Real-Life Criminal Investigations
AU - Elaad, Eitan
PY - 1990/10
Y1 - 1990/10
N2 - The present study provides a first attempt to estimate the validity of the Guilty Knowledge Test (GKT) in real-life criminal investigations. Skin resistance responses in GKT records of 50 innocent and 48 guilty Ss, for whom actual truth was established by confession, were analyzed by two methods. On the basis of an a priori decision rule, 98% of the innocent and 42% of the guilty Ss were correctly classified. Signal detection measures based on various possible decision rules indicated that the distribution of guilty Ss was highly differentiated from the distribution of innocent Ss. An optimal decision rule yielded correct classifications for 94% of the innocent Ss and 65% of the guilty Ss. These results suggest that the GKT could be a useful investigative tool that protects innocent suspects from being falsely classified as guilty. The false-negative identifications were accounted for in terms of the realistic conditions.
AB - The present study provides a first attempt to estimate the validity of the Guilty Knowledge Test (GKT) in real-life criminal investigations. Skin resistance responses in GKT records of 50 innocent and 48 guilty Ss, for whom actual truth was established by confession, were analyzed by two methods. On the basis of an a priori decision rule, 98% of the innocent and 42% of the guilty Ss were correctly classified. Signal detection measures based on various possible decision rules indicated that the distribution of guilty Ss was highly differentiated from the distribution of innocent Ss. An optimal decision rule yielded correct classifications for 94% of the innocent Ss and 65% of the guilty Ss. These results suggest that the GKT could be a useful investigative tool that protects innocent suspects from being falsely classified as guilty. The false-negative identifications were accounted for in terms of the realistic conditions.
UR - http://www.scopus.com/inward/record.url?scp=0000329018&partnerID=8YFLogxK
U2 - 10.1037/0021-9010.75.5.521
DO - 10.1037/0021-9010.75.5.521
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AN - SCOPUS:0000329018
SN - 0021-9010
VL - 75
SP - 521
EP - 529
JO - Journal of Applied Psychology
JF - Journal of Applied Psychology
IS - 5
ER -