In een redactioneel artikel geeft de redactie een toelichting op het tijdschriftnummer in kwestie.

Radicalization and terrorism remain areas of special interest in terms of security policies. It’s common knowledge that most of the activities related to radicalization and terrorism heavily rely on the involvement of multiple actors. Therefore, an increased understanding of the underlying social structures is considered to offer important leads for the development of effective countermeasures (in particular when related to demographic, cultural, psychological and other social factors). Yet, the number of empirical network studies in this domain (at least those openly available) that incorporate arithmetic tools known as Social Network Analysis (SNA) remain extremely scarce. In this paper the author presents an exploratory Social Network Analysis of the Hofstad network based on publicly available data. Members of the Hofstad network, a radical Islamist network in the Netherlands, were active recruiters for the violent jihad, spreaded radical propaganda, some attended training camps in Pakistan, and the network was suspected of planning several terrorist attacks on strategic objects and prominent people in the Netherlands. One of the members, Mohammed B., was sentenced to life in prison for murdering the Dutch filmmaker Theo van Gogh in November 2004. Although the Hofstad network was considered by trial as a terrorist organization in the first instance in 2006, the judgment was reversed on appeal in 2008 when most members were acquitted. As is characteristic of home-grown networks, our analysis indicated that the Hofstad network (N=67) was relatively sparse and decentralized and evolved around a more cohesive core of key players (N=13). The key players were identified based on their central network position and a hierarchical clique analysis. Mohammed B., who had been considered a marginal player by the secret service, turns out to be the most central actor of the network. Although the analysis clearly suggests that quantifying network structures provides actionable intelligence, more research is needed to validate the results.

The social network approach is gaining influence among criminologists studying organized crime and terrorism. The theoretical concept, however, still needs further elaboration. To this end, concepts developed within the field of economic sociology could provide a substantial contribution. Economic sociologists have, among other things, focused on the role of social networks with regard to the completion of economic transactions. They regard mutual trust built through personal relations as an essential part of economic transactions, particularly if these imply certain risks for the parties involved. In other words, before transactions materialize, the parties must first be able to establish trustworthy personal relations. Based on these ideas, Spapens introduced in 2006 the theoretical concept of the criminal macro network, being a social network consisting of individuals able and willing to engage in illegal activities. The capital of each member of the criminal network consists, on the one hand, of his links, defined as information relations, within the network. On the other hand, a person’s position is determined by personal knowledge and skills. It is assumed that executing an actual illegal activity – e.g. drug production, trafficking human beings, bank robbery – requires cooperation between a subset of members of the criminal network, the criminal group.An extensive study of xtc production in the south of the Netherlands between 1996 and 2004 revealed the existence of a ‘xtc network’ consisting of individuals interconnected by social relations. The macro network proved to be relatively stable over time. The composition of the criminal groups, however, changed regularly. This was not only explained by shifting business opportunities, but also by the efforts of the police and the Public Prosecution Service leading to convictions and the dismantling of criminal groups. Better knowledge of the functioning of the criminal macro network can provide valuable contributions to criminological understanding of organized crime. These insights are of course also of great practical importance for law enforcement agencies.

The literature on using Social Network Analysis (SNA) in criminological research is expanding. The SNA perspective already changed the way we look at organized crime. More often organized crime is referred to as changeable social networks instead of hierarchical structured organizations like the Italian or American mafia. In this respect, SNA seems to lack behind in empirical research on organized crime. Mainly, this is due to the lack of suitable network data on organized crime. For obvious reasons, commonly used methods of gathering network data – such as questionnaires – are less suitable for research on organized crime. Suspects of organized crime have not much to gain from talking about their ‘comrades in crime’. Alternative data need to be explored. Wiretaps from criminal investigations are one such source. In this contribution the SNA perspective is used to present an overview of the possibilities and limitations of using wiretaps for SNA. It follows that wiretaps from criminal investigations should be regarded as ego-centered network data. Therefore, research questions and objective for both criminal investigations as well as scientific research should be directed to the personal networks of suspects instead of the network as a whole.

In this paper, recent social network research in the area of juvenile delinquency is reviewed. Two main subjects are distinguished: first, studies in which Social Network Analysis is used to enhance our insights into the relation between delinquent peers and own delinquent behavior; second, the use of Social Network Analysis to get a better picture of delinquent groups and youth gangs. Two examples of social network analyses in the field of juvenile delinquency are elaborated. These examples combine visual depiction of networks with quantitative analyses of network characteristics, illustrating the complementary nature of both approaches. The literature and the examples show that Social Network Analysis lead to a more nuanced and complex insight into the role of delinquent peers in delinquent behavior and the structure of groups of young offenders.

Public Private Partnerships (PPS) are becoming one of the most popular answers to problems of crime and disorder. In this contribution, the authors research the Collective Shop Ban, maybe the most successful form of Public Private Partnerships currently operating in the Netherlands. A Collective Shop Ban is a civil measure bestowed upon a person by the shop owner, when s/he displays ‘unwanted behaviour’. As a consequence entry can be denied for every shop assembled in the association of entrepreneurs. In 2007 almost 900 people have been denied access to over 450 shops in the city centre of The Hague. This new form of collaboration between police, public prosecution service and entrepreneurs has already been rewarded with the Regional Crime Control Platform ‘safety award’. However, the authors question the effects of this collaboration. They argue that the Collective Shop Ban creates its own public of ‘unwanted shoppers’, that can be banned from a shopping area by devising new terms of exclusion. This ‘public’ is subjected to new means of power, to be applied by private security guards and shop owners. While entrepreneurs celebrate the possibilities of this civil measure, the authors warn for the juridical and ethical consequences of this measure.