Although many studies have investigated the backgrounds of people who went to Syria to join jihadist groups, much remains unclear about the underlying radicalisation processes. Many authors have noted that radicalisation and terrorism are associated with involvement in crime (the crime-terror nexus), in particular with membership of delinquent groups. However, it is unclear how this relation can be explained. This study was designed to increase insight into how the actual radicalisation process took place in one specific youth network in the Netherlands with a high prevalence of crime, and what triggered young people from this network to get involved in travelling to Syria. Based on police records, documents and interviews, we conducted a case study in a Dutch city in which twenty people went to Syria to join jihadist groups in early 2013. Most of them were involved in a troublesome youth group in a deprived multi-ethnic neighbourhood. We trace how a subgroup of this youth group radicalised, and how they made a connection with the jihadist network in the larger region. The results suggest that not only experiences of deprivation contributed to the radicalisation process but also the presence of persons with earlier ties to the jihadist network, as well as trigger events that led to existential questions and elevated susceptibility. Marriages with radical young women involved in the sister network also seem to have contributed to an overlap between this local youth group and a wider jihadist network. Furthermore, relatively criminal members gained status in the youth group by getting involved in jihadism. The results suggest that maintaining contact with youths at risk of radicalisation should be central to local prevention efforts. Radicalisation through trigger events and recruitment by jihadist propagandists could be prevented with specifically targeted interventions.