The present thesis aims at identifying a specific type of discourse about violence: the stories of adherence to drug trafficking, their emergence in the research context and the processes of identity construction resulting from such context. The data presented here comes from field work taken during 2009 in one of the main prison institutions in Brazil. Interviews were made with inmate members of criminal gangs of Rio de Janeiro who attended the prison school. These interviews were then qualitatively analyzed, from a micro-perspective approach, in the light both of the studies on oral narratives, based on interactional sociolinguistics, and of identity studies, especially those which consider narrative discourse as a privileged locus for social identities construction and analysis. Following most poststructuralist theories that dessencialize the concept of identity and bet on its symbolic dimension, the concepts of deviance and stigma are particularly productive in this study and traverse the three foci of analysis proposed. Firstly, following an interactional approach, special attention is given to the mixed meeting between the researcher and her interviewees, privileging the strategies of manipulation and invisibilization of the stigmatizing signs that menaces the interactional balance and the positive presentation of self. Analytical categories such as face work were used to interpret interactional sequences marked by the discursive neutralization of the experience of deviance. Secondly, the analysis describes the structure of narratives of adherence to drug trafficking and focuses on their systems of coherence, i.e., the way sequential ordering and causality relations constructed in these stories relate to culturally established discourses. Therefore, in such narratives, inmates negotiate the extraordinariness of deviance based on systems that explain criminality as related to external factors to individual agency. At last, the third axis of analysis situates prison discourse in the discursive and ideological debate which sustains such discourse, calling attention to the way prison voices position themselves and face, by means of discourse, the common sense thesis about a perverse instinct inhabiting criminals.