This paper recounts the daily work of the National Observatory of Delinquency (OND), which was established in 2004 by the French Ministry of the Interior both to collect and distribute data, often scattered and fragmentary, on the statistical evolution of crimes and offenses, and to improve crime prevention and crime-fighting measures. It explains the socio-technical constraints of bringing together policing data by the national police and gendarmerie, and it insists on the Ministry of Justice’s reticence. This article shows how mobilizing national victim surveys, conceived as alternative data to the traditional bureaucratic tools, disrupts the general process of harmonization and integration. It illuminates the meanders of the unfinished implementation of a “constituent administrative activity” in a highly politicized context.