We experimentally evaluate a community-level intervention designed to improve security by: increasing civilian state presence on the street, empowering community organizations to solve conflicts, and raising trust and cooperation with the state (versus local gangs).In 40 of 80 neighborhoods, Medellín's city government dramatically intensified normal governance services.After 20 months, there was no average impact on its legitimacy or local security.A prespecified analysis shows important heterogeneity, however.In neighborhoods where the state began weak, the state underperformed and opinions worsened.In neighborhoods where the state started strong, the effort raised state legitimacy and reduced crime and emergency calls.