This study aims to illuminate the processes that make individuals engage in organized crime activities. Within the diversity of individual involvement processes, several distinctive mechanisms are discussed. Theoretical ideas are illustrated by empirical data on 15 crime groups, including over 300 offenders. The crime groups differ in size, composition, and the nature of criminal activities. Social capital theory is used to understand the dynamical process of becoming involved in organized crime; on the one hand an individual contributes to a crime group, on the other hand the crime group helps an individual reach certain goals. Case studies reveal several resources, such as knowledge, skills, and equipment, that make offenders suit and contribute to a particular organized crime group. Criminal and conventional histories of organized crime offenders turn out to be diverse. Several joint characteristics that opened doors to organized crime opportunities, like running one's own business, are discussed. It is confirmed that involvement through family and long-time friends is common; most criminal groups contain at least one or two relatives. © 2012 Springer Science+Business Media Dordrecht.