The law enforcement behavior of the subject of decision-making in criminal proceedings has developed a certain algorithm in the system of criminal procedure law. Many probabilistic bases existing in the Russian legislation for making procedural decisions, rating expectations of the variable outcome of a procedural decision in a criminal case - all this provides for the need to introduce mathematical methods for researching the actual circumstances of a criminal case, their classification structure and logical justification. The purpose of the research is to identify the features of digitalization of the decision-making process in criminal proceedings. The research used a system of scientific methods, which is based on the principle of consistency, an institutional approach and sociological methods, which made it possible to evaluate the institutional basis for the introduction of mathematical and information and communication methods in the decision-making process in criminal proceedings. In the context of this problem, the authors pay special attention to the blockchain technology, this is a continuous sequential chain of blocks built according to certain rules, containing information, access to which excludes data theft, fraud, violation of property rights, and invasion of the system of making criminal procedural decisions. In the course of the research, they show the main institutional directions in the process of algorithmization of criminal procedure decisions. The article concludes that by applying a universal mathematical language in describing legal phenomena, quantitative values and statistical indicators, the subject of law is able to calculate the optimal correct decision in specific conditions in a criminal case.