This chapter demonstrates the use of the case study for criminal law. Working through the experience of doing a case study of a Dutch criminal court, the authors demonstrate the intricacies of making theoretical, methodological and practical choices and the consequences of these for the ‘case’ they were eventually able to make. The authors used as their guiding research question how judges of a magistrate’s court in the Netherlands arrive at their decisions as a matter of everyday work practice. By opening the black box of sentencing, the authors aimed to complement survey research and experimental research design, which tends to problematically isolate the impact of legal and nonlegal factors on sentence outcomes and to ignore the processes and mechanisms that take place in between. They also sought to challenge juridical understandings of adjudication and sentencing that understand these activities as purely cognitive or intuitive leaps in the rule-governed dark.