The relations between police and criminal justice are analysed by many theoretical and empirical studies in criminal sciences. The judiciary should, in normal conditions, be an instance of control of police activity, just as it is the guardian of guarantees and fundamental rights. In practice, however, much evidence shows that police knowledge and practices are validated by authorities in the justice system and in legal proceedings, which are often unchallenged. In Brazil, for example, research indicates that police testimonies are central in the conviction of certain crimes and that practices of institutional violence promoted by the police are still frequent and agents involved are not usually taken accountable. How could such reality be explained? In this paper, we try to work with the hypothesis that, in Brazil, the police have played a central role in punitive control since their inception in the 19th century, and that they have constituted themselves as a sovereign force on the streets dealing with "public disorder", an issue that was defined based on structural racial hierarchies of the Brazilian society. Therefore, often in an authoritarian way and in defiance of the law, the police developed their manner of action "at the streets" and the judicial system remained distant, as accomplice, or rarely rose to build control mechanisms. To work through these issues, we analyzed the speeches given at the Judiciary-Police Conference held in Rio de Janeiro in 1917. That meeting, which brought together police and judiciary authorities to think about the problem of crime in Brazil, addressed the tension between the increase in crime and the alleged excess of freedoms conferred by law. Being so, the speeches may carry along interesting insights to think how police forces and the judiciary had rather convergent then conflicted interests, practices and objectives.