Abstract : In many developed countries the proportion of convicted individuals belonging to stigmatized minorities is much larger than the share of these minorities in the overall populations. We explore whether socioeconomic status may explain this overrepresentation in the criminal justice system through the analysis of individual characteristics and sentence outcomes of juveniles convicted for serious crimes in Isére (one of the 96 French Metropolitan Departments) in the 20-years period ranging from 1985 to 2005. Serious crimes (liable to imprisonment) have a higher clear-up rate than petty crimes, and are thus probably less biased by police differential selection, one of the reasons invoked to explain minorities over-representation. The majority of juveniles in our database live in urban areas and, according to our estimations based on the parents' socioeconomic status, they are also a majority to live in households below the poverty threshold. Restricting to this subpopulation, we do not find any evidence of over-representation: the proportion of juvenile offenders belonging to minorities is of the same order of magnitude as their share in the overall urban juvenile population living below the poverty threshold.