An important character in Rio de Janeiro drug trafficking scene during the 1970’s and 80’s, Ailton Batata from Cidade de Deus, goes from outlaw to a case of study. His story of disqualification told in the movie Cidade de Deus (City of God), including a 15-year stretch in prison, is transformed by the work of two researchers. Away from crime, he can say something about the world of transgression.