In spite of the SAPS having a dedicated polygraph capacity since 1998, little research has been conducted with regard to the use of the polygraph in criminal investigations. Consequently, the aim of this research was to focus on the perceptions and experiences of investigators in the SAPS regarding the application of polygraph testing in criminal investigations, the application of the polygraph as an investigative aid, the extent to which it is used by SAPS investigators to resolve criminal cases opened by the general public and/or in internal departmental criminal investigations; and whether or not it has helped to solve cases by giving direction and/or focus to the investigator when an investigation is at an impasse. A qualitative research approach was conducted among investigators within the SAPS. The research design selected for this study was grounded theory. The sample consisted of twenty investigators, ten of whom had previously used polygraph examinations in their investigations and ten of whom had not. Data was collected from interviews, document analysis, field notes and memoranda which presented and detailed the perceptions and experiences of investigators in the SAPS regarding the application of polygraph tests in criminal investigations. / Criminology and Security Science / M.A. (Criminology)