Since the early 1990s, cross-border police and judicial cooperation has become a very important domain of the European Union. The Lisbon Treaty – if accepted by all the Member States – will certainly be a major stimulus to its further development in the field of internal security as well as in the field of external policy. In any event, the recent proposal for a new third comprehensive policy programme with regard to the Area of Freedom, Security and Justice – the so-called Stockholm Programme – foreshadows some of the changes the Brussels institutions and the Member States would like to embrace in the coming years. This book contains the contributions of scholars and practitioners to a conference on the future of police and judicial cooperation in the European Union that took place in November 2008 at Tilburg University. Referring to what has been achieved in this domain since the Treaty of Maastricht, these papers not only assess the proposals that have been put forward in successive policy documents relating to the Stockholm Programme, but they also pinpoint to the ongoing problems in the theory and practice of police and judicial cooperation within the European Union and to the ways in which these questions could best be solved.