The Interrelation Between the EU Charter of Fundamental Rights and the Schengen Agreement: The Ne Bis in Idem Example Through the CJEU Case Law

The ne bis in idem principle is of fundamental nature to the legal order of every democratic society. The concept of this principle refers to the prohibition, on behalf of State authorities, on prosecuting the same person more than once for the same conduct. In two preliminary ruling procedures, the national courts set questions to the Court of Justice regarding the compatibility of articles 54 and 55 CISA respectively with article 50 of the EU Charter of Fundamental Rights. In the first case, the Court ruled that article 54 CISA is compatible with article 50 of the Charter whilst, in the second, the Court, essentially, found unnecessary to reply to the question. The aim of this paper is to offer a review on the impact of these two judgments in the formulation of article 50 of the EU Charter and subsequently, propose an alternative approach on the interpretation of this provision, in line with the core of the ne bis in idem principle, in order to underline the significant role of the Charter in the future of the Union.