This thesis aims to analyse how Brazilian Criminal Law, taken as a discourse, contributes to legitimate the peculiar forms of violent operability of its penal system upon adolescents and mentally disordered offenders. The normative and dogmatic problems of inconsistency and fragilities over the capacity of culpability (imputability) and its negative are related to this empirical problem, and that is why the thesis also aims to verify if it is possible to rethink the theory of crime regarding the guarantee of those subjects human and fundamental rights; and, if so, in what terms. The theoretical references adopted are the marginal realism, the teleological-reductive functionalism, antipsychiatry and psychiatric reform movements in general, and the latin-american critical criminology. Therefore, firstly, the thesis investigates the historical development of the discoursive constructions about the absence of culpability by reasons of age and mental disorders in Brazil, as well as the making of its respective tutelary systems of correctional and therapeutical measures since the Empire to this day. In sequel, the main alternatives and inovations formulated within theory of crime are analysed, specially concerning the capacity of culpability. In conclusion, the thesis states that capacity of culpability – imputability, in fact – is an autonomous element within the analytical structure of crime, gifted with its own material basis, conceptualization and systematic position, which implicates changes in theory of crime and the system of punishments and correctional measures.