International cooperation in criminal matters in the European Union has grown exponentially over the past few decades. Importantly, there is a wide variety of authorities involved therein, rendering the traditional distinction between police and judicial cooperation outdated. Furthermore, its rapid growth exposed this policy field to inconsistencies and incoherence. Additionally despite the wave of new legislation, important lacunae can be identified, setting important challenges for the future. The combination of these issues clarifies the title of this book: there is a pressing need to rethink international cooperation in criminal matters.In answer to a call from the European Commission, the authors have designed a comprehensive methodological framework to review the entirety of international cooperation in criminal matters, combining desktop reviews, expert consultations, member state questionnaires and focus group meetings in each of the member states to obtain a comprehensive overview of the currently experienced obstacles and future policy options that are both needed and feasible. Over 150 individuals contributed to the study, with different background, including academics, lawyers, policy makers, police, customs, intelligence services, prosecution, judiciary, correctional authorities, Ministries of Justice and Home Affairs.This book provides an overview of the research findings and the recommendations formulated. They include but are not limited to(1) a helicopter view on cooperation with criminal justice finality,(2) a clear demarcation of the role of the judicial authorities,(3) a comprehensive review of refusal grounds, including proportionality and capacity concerns,(4) an assessment of gaps in the current body of instruments regulating international cooperation in criminal matters and possible remedies thereto,(5) a well-considered further development of Eurojust and(6) ensuring EU wide effect of mere domestic actions.Essential reading for both EU policy makers and for all practitioners involved, this book represents the first overall analysis of the entirety of international cooperation in criminal matters in the EU. An analysis aiming at moving beyond actors, bringing logic back, footed in reality.