This chapter sets up the puzzle of how governments in weak institutionalized democracies regulate criminal markets and achieve relative order. While Latin America is the most violent region in the world, its criminal violence varies according to informal state responses to illicit markets. I collapse these responses into four types of informal regulatory arrangements: particularistic confrontations, particularistic negotiations, coordinated protection rackets and coordinated coexistence. A further intrigue is how elected politicians are able to contain drug-related violence with inefficient police departments prone to corruption and human rights abuses. I unpack the relationships between politicians and police, showing that different regulatory arrangements emerge from various combinations of political competition and police autonomy. This chapter then specifies the study’s research design and scope conditions (i.e., weakly institutionalized democracies) and lays out the plan for the book.