Is a new constitutive rule born or rather brought to life? Interpreting admissibility of evidence based on the judgment of the CJEU in the EncroChat case

The article analyzes the admissibility of evidence under Directive 2014/41/EU, focusing on a new constitutive rule for evidentiary action recognized by the Court of Justice of the European Union in the EncroChat case (C-670/22) on April 30, 2024. It begins by introducing the concept of constitutive rules, particularly from the Polish Poznan School of General Theory of Law. The article then summarizes the ruling in the EncroChat case and examines its implications as a source for the new evidentiary rule within the European Investigation Order (EIO). Finally, it discusses the benefits of incorporating constitutive rules into the practical discourse on evidence admissibility, contributing to broader reflections on legitimate sources of such rules in legal systems.