Editors' introductionMaking sense of the commission of different kinds of crime lies at the heart of much of criminology. While criminals are often thought of and analyzed in individual terms though less so in the case of so-called organized criminals [13, 97], it has become clear through Edwin Sutherland's [12] work on differential association, among other works in criminology and the social sciences, that criminal motivations and techniques are acquired through social relations. That is, people tend to learn from each other how to commit particular kinds of crime. It is also apparent from common observation as well as criminological studies of co-offending that many crimes are committed jointly by two or more people, whether once only or more frequently over time. This relational quality of crime, and the emergence of enduring patterns of criminal co-offending, remind us that crime is typically socially embedded, that crime is often a social activity among other social activities in which individuals engage. In short, the extent and kind of social relationships an individual has will influence whether, and how, he or she decides to get involved in criminal activity and whether this activity is recurrent or limited to one occasion. Given this relational reality of most forms of crime, indeed "[i]t is surprising", as Coles [3: 580] noted, "that a set of techniques developed specifically to investigate 'relational data'.. and derived from the likes of kinship patterns, community structures and interlocking directorships has not proved more attractive to those researching serious crime groups". The set of techniques Coles refers to are those of social network analysis (SNA).The neglect of network analysis by criminology has diminished significantly in the past decade. A number of scholars in North America and Europe have built upon