This thesis shall contribute to European Criminal Procedure, a rapidly evolving area of EU policy that has attracted much attention, but has also been subject to criticism. The research will first identify and analyse the main rationales of this area. Since the Tampere European Council of 1999, mutual recognition has become the most fundamental concept of judicial cooperation in criminal matters and has experienced a steep career, having been adopted by Art. 82 TFEU. When the principle of mutual recognition was introduced, it was based on an analogy to the free movement of goods. This analogy has often been regarded as flawed. Moreover, there has always been a notion of mutual recognition in judicial cooperation as well. The study will show how these two factors have influenced the development of the area, and how policy concepts, such as the principle of mutual trust, have had a greater influence on the development of the law than any legal doctrine. The lack of a coherent approach to the area of judicial cooperation and the unsystematic combination of different legal orders have caused unforeseen frictions for the individual. These will be illustrated by an analysis of the law of transnational evidence-gathering according to the European Evidence Warrant and the proposed European Investigation Order. It will be shown that most of the problems result from the lack of a uniform allocation of jurisdiction and from an overly confined understanding of fundamental rights in the context of judicial cooperation. By analysing the nature and purpose of jurisdictional rules in a national and a European context, the thesis aims at uncovering the theoretic foundations on which a uniform allocation of jurisdiction could be built. Finally, the thesis analyses the role of fundamental rights in judicial cooperation. It will uncover the ineptness of a nation-state oriented interpretation of fundamental rights to adequately address the problems of mutual recognition and argue for a European understanding of transnational judicial rights.