Reprinted from the Scientific Journal
Criminalistics and Court Expertise
2012 Annual Issue, Number 57
James L. Chapman, Professor Emeritus Former Director of Forensic Crime Laboratory State University of New York at Corning, NY USA
Scientific Consultant, Research Analyst
FIELD EVALUATION OF EFFECTIVENESS OF VSA (VOICE STRESS ANALYSIS) TECHNOLOGY IN A US CRIMINAL JUSTICE SETTING
This research paper represents 18-years of data evaluating the use of the VSA technology for the detection of stress associated with possible deception. Using a combinatorial approach of VSA and a standardized questioning process, an expert obtained the results of stress detection associated with criminal activities, which are proven in 95% of cases. On the other hand, there were no cases when a confession was obtained in the absence of stress. In particular, the most considerable stress levels were detected during the investigation of murder cases, grand larceny and sexual crimes. When the VSA technology was used for diagnostic purposes to predict deception, positive results were obtained in approximately 95% of the cases. Additionally, a strong, indirect relationship (approximately 94%) was discerned between jeopardy (crime consequences) and confession rates among guilty suspects.
The implications of the findings for the suitability of VSA as a deception detection tool in the field are discussed.