Arjan Blokland is senior researcher at the Netherlands Institute for the Study of Crime and Law Enforcement, and professor of Criminology and Criminal Justice at the Institute for Criminal Law and Criminology, Leiden Law School, Leiden University, The Netherlands. At the time of editing this volume he was Obel visiting professor at Aalborg University, Denmark. His research interests include criminal careers and life-course criminology, criminal networks and organized crime. Klaus von Lampe is a professor of criminology at the Berlin School of Economics and Law in Berlin, Germany. He has previously been a professor at John Jay College of Criminal Justice, City University of New York. His research interests include the conceptual history, theory and empirical manifestations of organized crime as well as crime prevention and international law enforcement cooperation. For his book 'Organized Crime: Analyzing illegal activities, criminal structures, and extra-legal governance' he received the Outstanding Publication Award from the International Association for the Study of Organized Crime. Sjoukje van Deuren is assistant professor at the VU School of Criminology, Faculty of Law, Vrije Universiteit Amsterdam, the Netherlands and postdoctoral researcher at the Netherlands Institute for the Study of Crime and Law Enforcement (NSCR). Her research interests include organized crime, criminal networks, and outlaw motorcycle gangs.