The purpose of this article is to advocate for new methods of studying international law. Hissène Habré, former President of Chad, was convicted by a hybrid tribunal in Dakar. Our book on this judicial process (The President on Trial: Prosecuting Hissène Habré, Oxford University Press, 2020) develops a novel empirical format of first-person testimonials, followed by expert analyses, to trace and contextualize the decades-long story of attempts to bring Habré to justice. The empirical materials collected in our book demonstrate that the Habré trial challenges a linear distribution of power from international (global) actors to local, demonstrating rather a series of horizontal relations between the local and international. Based on this research experience, the article lays out the method we developed. It facilitates an assessment of the legal and political impact of court decisions, routines and broader bureaucratic politics through which the practices of judging are constructed. Justice does not speak with one voice; it is made up of multiple actors with different professional interests and personal goals. It is also impacted by power dynamics and by the structure of the institution, including by institutional routine and legal bureaucracy.