Significance of pre-test interview in polygraph examination

Societies had been struggling against deception and trying to detect it until finally, in the twentieth century, an increasingly popular technique was developed - the use of polygraph. Used for police purposes, but also more and more frequently for private purposes, polygraph inspires trust and offers possibility of detecting whether a person is being dishonest or not. Polygraph does not detect lying, but rather records physiological responses which have been proved to accompany lying and emotional stress. Although polygraph examination consists of three stages, the interrogation being crucial, one should not disregard the significance of the first stage in which the examiner establishes a relationship of trust with the examinees, evaluates the basic pattern of their behaviour, explores the examinees' familiarity with crime, but also their familiarity with the functioning of the polygraph. The pre-test interview is an opportunity to gain new findings but also to detect errors and omissions that have occurred in the operative activities preceding the examination. A study that conducted within the Police Directorate of the City of Belgrade including 270 respondents confirmed that issues arose in the course of examination when the test was not sufficiently prepared and when the pre-test interview was not given sufficient attention. The presentation of obtained findings regarding the errors and omissions detected in the pre-test interview are aimed at familiarizing operatives with the procedure and problems related to polygraph examiners' giving findings due to previous omissions, in order to make their cooperation better and more efficient.