The article discusses the role for systemic and particular deficiencies in EU criminal law. It does so by analyzing in depth that law as regards the European Arrest Warrant (EAW), but also across measures of EU criminal law that have not yet been explored under this light. While the attention of the literature has been mainly on the EAW and the way those deficiencies can led to refusing the execution of the warrant, a wider assessment reveals the existence of a latent law of the systemic and the particular in this field. The conclusions reveal that the understanding and application of systemic and particular deficiencies in EU criminal law have significant implications in terms of the principle of mutual trust and the complex interaction between different EU values.

More than any other EU institution, the Court of Justice of the European Union has upheld the presumption of mutual trust in EU criminal law cooperation. Surprisingly though, despite mutual trust’s centrality in the Court’s jurisprudence, it has long not qualified nor properly elaborated the notion of trust, but rather held on to its presumed existence based on a high level of fundamental rights protection throughout the Union. This article will assess the important role of the Court in establishing, upholding and ultimately qualifying the trust presumption in the EU criminal justice context. Along the lines of a number of key cases, the narrative of a strong defence of (the presumption of) mutual trust appears, but also of an evolution toward more room for rebuttal in recent cases. This signals the increased weight given to fundamental rights protection in the EU’s Area of Freedom, Security and Justice.

The concept of a European prosecution service operating within a single legal area as proposed by the 1997 Corpus Juris study aimed to tackle impediments to the prosecution of budgetary fraud cases in the transnational context. Subsequent compromises shifted the focus of negotiations from creating a European prosecution service with uniform powers to the integration thereof into the divergent national legal systems. This paper analyses relevant documents up to the draft endorsed by the 2015 Luxembourg Presidency and concludes that the scene is set for autonomous and binding Union decisions to prosecute budgetary fraud at national level. Nonetheless, the low-level of Europeanisation coupled with an increasingly complex model and no real scheme to tackle the fragmentation of national criminal laws fail to enable effective and consistent prosecutions of EU budgetary fraud.