This book contains the results of a research project on the protection of fundamental rights in transnational inquiries in criminal matters. This project was promoted by my chair of Italian and European criminal procedure at the Law School of the University of Messina, jointly with the University Consortium Megara Ibleo (CUMI) of Priolo Gargallo and the Bonino-Pulejo Foundation of Messina and with the kind sponsorship of the Decentralised Professional Training Office of the Supreme Council for the Judiciary (CSM) from the Catania Judicial District, the Syracuse Bar Association and the Messina Section of the Italian Young Lawyers Association (AIGA). In June 2011, in the context of this project, an international conference took place in Syracuse, where distinguished scholars of international and European criminal law and practitioners from eleven countries both from inside and outside Europe met to expose and discuss the provisional results of their investigations. This book brings together the final surveys from a four-level perspective. Many things have happened since the beginning of the present research, especially the death of two outstanding scholars of Italian criminal procedures, namely Prof. Vittorio Grevi and Prof. Giovanni Tranchina. As a consequence of this, I have chosen to dedicate this project to both of them, in memory of the high human and scientific value of these two Masters. Furthermore, today I would also like to remember Prof. Dr. Gu¨nter Heine, who took part actively in this research but unfortunately could not see this book, since he died shortly after our conference in Syracuse.