NCJ Number
191344
Journal
Polygraph Volume: 30 Issue: 1 Dated: 2001 Pages: 16-28
Editor(s)
Donald Krapohl
Date Published
2001
Length
13 pages
Annotation
This study assess the accuracy of the Control Question Test (CQT) and Guilty Knowledge Polygraph Test (GKT) in comparison with other common methods of identification. The study was also designed to resemble field conditions in a more accurate manner than the study by Widacki and Horvath (1978). Finally, the study considers additional criminal identification tests such voice identification.
Abstract
Criminal investigations conducted by the Israeli Police often use the polygraph as an aid for finding the guilty suspect or eliminating innocent suspects. Several methods of psychophysiological detection have been developed and used in field practice. These methods are based on a comparison between physiological responses to relevant questions (i.e., questions that focus on the issue under investigation) and some form of control questions. Two common methods are the focus of the present study: Control Question Technique (CQT) and Guilty Knowledge Test (GKT). This study compares the accuracy of these two major polygraph methods used in criminal investigations by the Israeli police, with other common criminal methods such as: fingerprint identification, voice identification, handwriting identification and eyewitness identification. Results show that three methods were free of false positive errors: fingerprint identification, the guilty knowledge polygraph test, and natural handwriting identification.