Brazil is currently undergoing a major transformation largely due to the economic development it has experienced over the last decade. On the one hand, unemployment rates of the new global player reached the lowest level in history in 2013, less than 4. on the other hand, such a scenario expresses renewed levels of social conflict, increasing criminal violence and incarceration. Based on ethnographic fieldwork which has been conducted since 2005 in the outskirts of Sao Paulo, the exposition presents a panorama of transformations in poor Brazilian neighborhoods and favelas from the 1970s until today. This overview gives empirical ground for a reflection on Brazilian development and its margins, focusing on both social conflict and social legitimacy that nowadays emerges from crime, or the criminal world, in urban outskirts.