Journal abstract
This article focuses on a challenge in the current terrorism literature, namely the methodological justification concerning the collection and analysis of empirical data. Lack of detailed methodological accounts of the collection and analysis of the data makes it difficult to evaluate presented findings, especially if these data are confidential or focused on specific aspects of the phenomenon. This article offers an extensive overview of the methodological procedures conducted in a large empirical research project on jihadist networks based on confidential police files (2000–2013), interviews, and trial observations. The article illustrates how grounded theory–based methods can be used to collect and analyze such data and to develop and test new theories in this research field