This article explores queer sexual policing in late Imperial St. Petersburg (c.1900-1917). The focus is on the street-level constables who bore the principal responsibility for policing male homosexual offenses in the city's public and semi-public spaces. This emphasis on the street-level policing of homosexuality contrasts with other discussions of gay urban history and the oppression of queer men by the authorities. The article draws on new evidence from precinct-level police archives to complement and challenge previous discussions of queer sexual policing in the Imperial capital. By taking the fate of queer men in an autocratic city, this article refines our understanding of the ways in which homosexual practices and identities emerged in modern times. Specifically, it builds on Michel Foucault's descriptions of constables as "arbiters of illegalities," where the term arbiter suggests rule-based and yet discretionary coercion. Here, the influential model of disciplinary policing of sexuality is complemented by an emphasis on the role of discretionary power in the history of homosexuality.