The article provides an overview of the main standards of evidence used in law enforcement practice at different stages of criminal proceedings. In the absence of a legal interpretation of the concept of “standard of proof, however, law enforcement agencies use this terminology. In the doctrine of criminal procedure, this issue is increasingly attracting attention. There is no single approach to defining the concept of “standard of proof ” in the existing scientific developments on this topic. The article identifies three basic standards that are applied at different stages depending on the decision being made (sufficient data, reasonable suspicion, and beyond reasonable doubt). At each specific stage of criminal procedural activity, a certain amount of information is required, which allows making a proper procedural decision. Most often, the law uses such concepts as “sufficient information, in the presence of other data-giving grounds”. “The availability of sufficient data-indicating…”, etc. Each such concept pre-supposes some kind of evaluative activity of the courts, his subjective discretion. Practically all the decisions cited in the article mention in one form or another the standards of evidence, to which the court refers not only the provision “beyond reasonable doubt (beyond any reasonable doubt)”, but also the principles of presumption of innocence, freedom of evaluation of evidence, emphasizing the evaluation of the properties of evidence, emphasizing the equal evidentiary value of each evidence in the case, and the lack of a hierarchy of such. Monitoring of practice allows us to conclude that in the decisions of the first and appellate instances there is an unambiguous approach to the content and application of the standard “beyond reasonable doubt, which assumes the absence of significant and irremediable doubts about the guilt of the accused person but does not mean absolute certainty of his guilt; existing doubts may exist, but they are negligible.