Possibility of retroactive effect of judicial interpretation of criminal law in the context of its legal certainty

The article addresses the issue of the possibility of retroactive effect of the results of judicial interpretation of criminal law in the context of its legal certainty. It is stated that the effect of a law in time is a manifestation of legal certainty. Predictability of a criminal law does not mean that this law should be understood equally by everyone and be certain and predictable for everyone. Accordingly, courts may interpret criminal law, the result of which should be predictable for the addressee. Based on the case law of the European Court of Human Rights, and also taking into account the theory of “legitimate expectations”, which is widely used, in particular, by the Court of Justice of the European Union, and the activity­based approach to the study of legal phenomena, the author proves that the issue of retroactive effect should be resolved not only with regard to the criminal law itself, but also with regard to the results of judicial interpretation provided by the Supreme Court, which is objectified in the form of legal conclusions set out in the Supreme Court’s rulings, which are binding on all public authorities which apply in their activities a legal act containing the relevant rule of law, and the conclusions on the application of the rules of law set out in the Supreme Court’s rulings are taken into account by other courts when applying such rules of law. If the result of judicial interpretation interprets the criminal law provision that was applicable at the time of the criminal offense more «rigidly», it does not have retroactive effect. If such a result of judicial interpretation is more favorable for the person who committed the criminal offense compared to the interpretation that existed at the time of the criminal offense, then such a result has retroactive effect. The new result of a judicial interpretation of a criminal law provision may have retroactive effect if such interpretation was foreseeable for the addressee of the criminal law and did not violate his legitimate expectations or violate expectations that were not subject to protection for specific reasons.