An overarching argument of the book, which connects its parts, is an epistemological one: to fully grasp the routine understandings, interpretations and practices that animate human rights law in policing, a sociological approach to law should be explored and experimented with. In sketching out what such an approach might look like, this chapter introduces the three conceptual foundations adopted and outlines the research methods deployed in the book. The first of these is how human rights law comes to be adopted and deployed as ‘vernacular’ beyond traditional legal forums and judicial audiences in order to both legitimate and challenge police power. The second is human rights law as a set of principles and standards that officers are socialized in, and engage in ‘sensemaking’ of, amidst their sub-cultures, everyday routines and organizational demands. The third is how human rights law comes to be ‘practiced’ by officers in specific roles in so far as they are professional actors required to bring a resolution to a specific factual issue through understanding, engaging with and applying human rights law principles and standards. Collectively, these features comprise the book’s sociological approach to human rights law.