The scientific article is devoted to the study of forensic knowledge, examples of their historical application in practice and the preconditions for their emergence. Despite the fact that in our time the achievements of forensic science are widely used in practice, there is a need to get acquainted with forensic knowledge and the prerequisites for their emergence, as the history of development and formation of criminology is closely linked with the latter. Forensic knowledge existed long before forensic science received the status of an independent science. That is why they constitute the content of modern criminology and need further research within the possibilities provided by historical sources.
 It has been established that in any period people committed crimes, violated established customs, traditions, rules of conduct, laws and norms. As a result, there has been and continues to be a societal need for conflict resolution, crime detection, identification and punishment. It is for this purpose that special (forensic) knowledge begins to be used and disseminated.
 A comparison of different scientific definitions of forensic knowledge is made, as well as the development of human need for the accumulation and use of knowledge, the separation of special knowledge from certain areas for their further application.
 It was determined that the emergence and development of forensic knowledge was associated with the need to identify the person who committed the crime and to find out the true circumstances of the crime. Thus, the disclosure of crimes began to involve knowledgeable people who had some knowledge to conduct research on certain processes, phenomena, events using special tools and methods.
 In addition, this article discusses some of the provisions of some ancient codes of law, which contain guidelines for the collection, investigation, evaluation of evidence, stages of criminal investigation, and so on. Occasionally, there are examples of historical cases that confirm the conduct and development of medical, chemical, psychiatric examinations, research into the authenticity of coins and documents. The existence of separate institutions is established, which were gradually endowed with expert powers, and later the creation of the first expert institution.
 The results of the article emphasize the precedence of forensic knowledge in forensic science, methods and practical areas of use of relevant knowledge, the prerequisites for their emergence.