The Conventional "Ne bis in idem" and the Burden of Proof: The Court of Cassation Clarifies with Judgment No. 17496/2025

The principle of "ne bis in idem", which prohibits being judged or punished twice for the same act, is a fundamental guarantee recognised both by our legal system (art. 649 c.p.p.) and at the European level (art. 4 Protocol 7 ECHR). This guarantee is particularly relevant when an individual faces parallel proceedings, such as criminal and administrative/disciplinary proceedings. Judgment No. 17496 of 16 April 2025 (filed on 8 May 2025) of the Supreme Court of Cassation intervenes on this delicate balance, outlining the evidentiary burdens on the appellant.

The "Ne bis in idem" between Domestic and Conventional Law

The prohibition of double jeopardy can present practical complexities, especially when comparing different types of proceedings. The European Court of Human Rights, in judgments such as *Engel v. The Netherlands* (1976) and *A. and B. v. Norway* (2016), has established precise criteria for assessing the compatibility of dual sanctioning tracks. These criteria consider the nature of the offences, the severity of the sanctions, and the substantial and temporal connection between the proceedings, aiming to prevent "double jeopardy" for the same conduct.

The Cassation Judgment No. 17496/2025: The Burden of Allegation

The Supreme Court, with the judgment in question, addressed the appeal of F. D. N., who alleged a violation of the conventional "ne bis in idem". The core of the decision concerns the appellant's burden to prove such a violation. The Court of Cassation reiterated an unavoidable principle:

In the context of an appeal to the Court of Cassation, it is incumbent upon the party alleging a violation of the conventional "ne bis in idem" principle, invoking the application of the criteria established by the ECtHR in the decisions Engel v. The Netherlands of 8 June 1976 and A. and B. v. Norway of 15 November 2016, to produce, on penalty of inadmissibility of the claim, the final decisions issued at the conclusion of the separate proceedings, which are essential for assessing their sanctioning scope and the illegitimate duplication of proceedings, one administrative or disciplinary and the other criminal.

This maxim is crucial: it is not enough to generically invoke the conventional "ne bis in idem". The appellant must attach to the appeal the final decisions of all proceedings (criminal, administrative, or disciplinary) that are considered to be in violation. Without these documents, the Court of Cassation cannot verify the "sanctioning scope" or the actual "illegitimate duplication" of the proceedings, rendering the appeal inadmissible. The burden of allegation is not a mere formality but a substantive requirement for a review of legality based on concrete evidence.

Requirements for an Effective Appeal

For an appeal to the Court of Cassation invoking the conventional "ne bis in idem", it is essential to:

• Produce the final decisions of all relevant proceedings.
• Clearly articulate the grievance, comparing the decisions with the ECtHR criteria.
• Demonstrate the connection between the facts and the potential double jeopardy.

Conclusions: Rigour and Protection of Rights

Judgment No. 17496 of 2025 by the Court of Cassation, presided over by Dr. A. P. and with Dr. I. P. as rapporteur, reinforces the need for a rigorous and documented approach. For those facing situations of potential "dual sanctioning tracks", it is essential not only to be aware of the "ne bis in idem" principle but also to prove its violation through precise documentary evidence. Only then will it be possible to obtain effective judicial protection and fully assert the guarantees offered by our legal system and European law.