The «Non bis in idem» Principle in the Practice of the European Court of Human Rights: transformational processes and contemporary challenges

This article analyzes the evolution of the “non bis in idem” principle (the prohibition against double jeopardy) from ancient times to its current stage of development in the case law of the European Court of Human Rights. This principle, enshrined in Article 4 of Protocol No. 7 to the Convention for the Protection of Human Rights and Fundamental Freedoms, guarantees protection against being subjected to double jeopardy — that is, being prosecuted, tried, or punished again under the jurisdiction of the same state for the same facts after a final acquittal or conviction. It is demonstrated that the literal text of this provision has been significantly expanded in the practice of the Strasbourg Court as a result of an autonomous interpretation of the concept of “criminal charge” (based on the “Engel criteria”). Currently, this prohibition also extends to administrative, tax, financial, and disciplinary proceedings if the relevant sanctions are de facto repressive and punitive in nature within the legal system of the relevant state. The content of the key elements of this principle is examined through the lens of the case law of the Strasbourg Court. Particular attention is paid to the development of the ECtHR’s approaches to the criterion of identity of material facts (idem) and to determining whether proceedings constitute prohibited duplication (bis) – from the case of “Sergey Zolotukhin v. Russia” (2009) to the recent decision in “Jesus Pinhal v. Portugal” (2026). It has been established that, to determine idem, the decisive factor is the comparison of the factual circumstances constituting the essential elements of the act, rather than the difference in their legal classification; at the same time, multiple “criminal” proceedings concerning identical facts do not necessarily constitute prohibited duplication if they form a properly integrated system. Using examples from the practice of the Supreme Court, the paper demonstrates the complexity of distinguishing between different legal regimes of liability in the Ukrainian legal system. It justifies the need not only to assess the factual identity and the substantive and temporal connection between proceedings but also to ensure coordination among competent authorities and the proportionality of the cumulative burden of the sanctions imposed. Recommendations are formulated regarding the consideration of previously applied measures within the scope of the courts’ current powers and regarding the improvement of the relevant legislative mechanisms.