Institutions should normally have an integrative influence. The family, for example, has the task of protecting and giving socio-emotional support to children, and schools should prepare young people for their future. Ideally the common goal of all of society's institutions is to secure the integration of youth and prevent or intervene against deviant behavior. But sometimes institutions provoke or even cause juvenile delinquency. The article discusses institutional influences and the role of the police in the criminal and violent situation in the "favelas" of Rio de Janeiro. Starting with an overview of the origins and the development of violence, crime, and drug trafficking in the "favelas", the authors show how these slums arose. Their analysis examines the lack of a state presence with an integration policy to avoid social disintegration. Instead of social integration policy, there is a dual approach that both controls and produces violence. The article also presents the first results of a government attempt in 2000 to introduce a new police unit to stop the violence and improve the social opportunity structure of the residents of the "favelas", especially young people. (Contains 24 notes.)