Likelihood Ratio in Evidential Evaluation of Polygraph Examination

2019

The starting point of the paper is the observation that the likelihood ratio (LR) is not used in the evaluation practice of — so important in the field of internal security — polygraph examinations. Meanwhile, LR is the only scientifically justifiable parameter that shows the evidential weight of particular evidence. The authors present theoretical attempts to use LR for evidential assessment of the polygraph examinations value and subject them to criticism. The main objective of the paper is to present the LR calculation procedure in the context of interpretation of a polygraph examination result treated as evaluative expertise. The following assumptions are made: the analysis includes onl…