The scientific basis, reliability, and validity of techniques for verbal detection of deceit

Abstract

The paper focuses on a comparison of three techniques mostly used for verbal detection of deceit. Criteria-Based Content Analysis (CBCA) is considered a scientifically grounded, standardized, empirically tested, valid and reliable technique for veracity detection of witnesses' and victims' accounts. Similar conclusions may be drawn for Reality Monitoring (RM) techniques, which have a comparable accuracy of 70% in making decisions about the veracity of analysed accounts, but it is considered less standardized. In comparison to the RM, which is not well tested in the context of crime investigations, the CBCA is a more time-consuming and professionally demanding procedure. Contrary to previously mentioned techniques, the Scientific Content Analysis (SCAN) is considered as a pseudoscientific procedure without sound scientific grounding, relying on uncorroborated assumptions by its proponents. It is an unstandardized technique, results of which are influenced by the subjectivity of interrogators affect in the results. Research shows that the SCAN technique is ineffective in detecting deceit, and furthermore, decisions made by practitioners are under the influence of their expectations and previously gained knowledge about a suspect. Criminal investigators should therefore be discouraged from using the SCAN technique due to its ineffectiveness. The technique also leads to chance guessing about deception of suspects and therefore, to unjustified exclusion of guilty suspects and to unjustified accusations of innocent suspects. In contrast, the CBCA and the RM are 70% accuracy, snf useful in criminal investigation; however, it should be emphasized that their results may have an indicative value for criminal investigators but no evidence value due to their deficiencies.