The ECJ's recent case law on ne bis in idem: Implications for law enforcement in a shared legal order

The ne bis in idem principle is a forerunner for fundamental rights in the European legal order. It has facilitated integration, but it also meets strong resistance. This contribution deals with the principle of ne bis in idem at the interface of administrative and criminal law enforcement, which has been a particularly controversial issue over the last few years. It analyses the recent case law of the ECJ and explores its consequences, focusing on the extent to which the principle has been made dependent on the degree of harmonization of EU law and on the transnational implications. With the rise of many new forms of transnational cooperation and an increasing focus of the EU legislature on law enforcement, the significance of this case law is hard to overlook.