The use of a polygraph in the investigation of criminal offences: problems of tactics and legal regulation

Today, there are changes in the criminal and criminal procedural legislation of Ukraine, forensic tactics and methods of investigating crimes are developing, new technical means and technologies are emerging that are useful in conducting investigative (detective) and covert investigative (detective) actions. One of these technologies is polygraph examinations using a special device designed to simultaneously record breathing, blood pressure, biocurrents of the brain, heart, muscles and other physiological processes, which in turn allows to determine the reliability of a person's testimony. The article examines the tactical and legal problems of using a polygraph in criminal proceedings, emphasises the absence of a streamlined solution at the legislative level which would regulate the procedure for using a polygraph, and notes the existing problems of compliance of popular polygraph models with the requirements of the State Standards of Ukraine. The article also analyses the case law on the issues of admitting the results of polygraph examination as evidence. It is determined that today there are two options for judges' attitudes to the results of polygraph use in general and to the conclusions of forensic psychophysiological examination using a polygraph in particular. The former includes court decisions which recognise the use of a polygraph as a source of evidence, and the latter includes decisions where the court does not support the use of this device and does not recognise it as evidence. The study provides a comparative analysis of the practice of using a polygraph in other countries. It is established that in developed countries there is also no single, unambiguous approach to the procedure for using a polygraph. The article identifies the need to improve the legislation on the use of polygraph in the activities of law enforcement agencies of Ukraine and to develop uniform standards for the training of polygraph examiners and methods of using polygraph.