Criminal justice systems sometimes err; such errors occur in every country, regardless of variations in legal and judicial systems and despite measures implemented to prevent them. Erroneous decisions are usually called unreasonable. This is not entirely true, because court decisions, irrespective of later reassessment, are evidence-based conclusions that represent the decision-maker’s belief about the circumstances of the case. Gettier cases, which challenged the definition of knowledge as justified true belief, are not only an unresolved puzzle in analytic epistemology but also serve as a model for the common errors that arise in criminal fact-finding. The analysis of the origin and structure of knowledge underlying judicial decisions undertaken on the basis of this model makes it possible to identify the dangers associated with the mechanism of formation of coherent procedural narratives that determine the content and orientation of judicial discourse. The requirement of comprehensiveness, completeness and objectivity of establishing the circumstances of the case, fixed earlier in Art. 20 of the Criminal Procedure Code of the RSFSR (1960), was an important mechanism for preventing such mistakes and its “dismantling” in the current criminal procedure law made modern justice more vulnerable. New information technologies are increasingly penetrating into law enforcement and judicial activities, create opportunities for searching, analysing and presenting information that are many times greater than the human ones. In a certain sense, these are machines for the rapid construction of coherent justifications that are not balanced by the same automatic mechanisms to ensure the correspondence of the obtained results. Therefore, new technologies and their impressive capabilities for searching and processing information amplify the risk of error and, in this respect, constitute a danger.