The subject. The authors create an instrumental apparatus that saturates existing and emerging data needs in the theory constituting process and thus create preconditions for police practice development.The methodology. The research is based on the content analyses of final research reports, the object of which is police proceedings and the subject is police reality,The purpose. The authors substantiate the following hypothesis. The source of the development of knowledge in police practice and the development of police theory is a permanent solution to the philosophical contradiction between police theory and police practice, with police practice being the defining aspect of this contradictory unity. The need and areas of scientific knowledge of activities in the police proceedings structure are therefore determined by police practice.The main results. By verifying police practice, the authors confirm the necessary obligatory interaction between theory and practice, which is predominantly determined by the achieved research outputs and their acceptance. At the same time, they respect that systematically processed knowledge from applied research can show the character of a theory. In accordance with their knowledge, consisting of a system of knowledge presented by the achieved outputs from scientific research, evaluation and explanation of phenomena registered in the purposeful implementation of activities in the structure of police proceedings (research object). The term police action can be understood as a synthetic term for a holistic grasp of the police activity and its bodies. The activity of police and security authorities means: a special form of professional service for the state, self-governing as well as commercial organizations and, last but not least, citizens. It contains a set of executive, organizational, management and other activities that have the character of official interventions, official acts, other official activities and other measures. They are carried out in accordance with the rule of law and ethical principles of civil democratic society, preventive and, where necessary, repressive methods of police work. Their aim is to protect the fundamental human rights of citizens and society from crime and other anti-social activities. They define the identity of these phenomena through the subject (optics) of research, systematically defining the police reality by the process parameters, their determinants and constructs of specific police activities. In the Slovak Republic, the authors of this paper participate in the performance of tasks related to the constitution of police sciences. The outputs of applied research offer a system of scientific knowledge about police reality. With the dialectical approach, in relation to the examined activities in the structure of police proceedings, they define the reasons related to the assumption of the existence of links among the elements of police reality, or they reveal their objective absence. By identifying systems, the authors create a model of these purposefully implemented activities with properties characterizing their behaviour. At the same time, they respect that the strategic form of the parameters of this model is expressed by the achieved set intentions and goals of certain specific activities. Determining them is a concentrated expression of this will. The basic context in their work (participation in the process of constituting police sciences), determining the meaning and mission, is a specific subject accepted by them. This is the police reality, an objective fact that the theory of police sciences examines and uses to explain existing and emerging objects. Therefore, their activity in the process of constituting police sciences corresponds to changes in social processes. When creating their instruments (conceptual system, categories, theoretical models, forms of thinking), they combine it with the explanation of new approaches related to the development and advancement of policing processes, characterized by openness and possibilities of social control in their purposeful implementation. This confirms that this process forms a system. Its design shows relative stability and closeness. They do not include any inputs in its content, just those that are foreseen and anticipated. In this context, they realize that the interdisciplinary of concepts enriches the view of constituted police science. For the police sciences , the abstractness and generality of statements from other scientific disciplines is not a starting point, but already the result of research into specific systems (disposition of knowledge), significantly contributing to increase effectiveness of their scientific work. In the conditions of the Slovak Republic, the police sciences are constituted as practical, social and security sciences. Therefore, the authors of this paper accept that the theoretical and methodological development of police sciences requires them to be confronted and independently dealt with the current state in the theory and methodology of science in the early 21st century, to be sensitive to the current development of the overall scientific atmosphere and independently and critically. In this process, the meaningfulness of their scientific work is evident. This corresponds to the registered needs for the transfer of scientific knowledge into police practice.Conclusions. From these findings it is clear that in the current stage of development of the Slovak Republic, the process of constituting police sciences forms a structured system with to the point management. Its successful completion is also determined by the results of a constructive discussion, the authors participated in with this presented knowledge.