This article describes and explains “police vigilantism” as a mode of authoritative extralegal coercion performed by public police officials conceived as doing their duty to realize justice in the world. Based on ethnographic observations, interviews, and content analysis of news and entertainment media as well as official government reports, this essay examines a specific form of police vigilantism in contemporary India known as “encounter killings”. Demonstrating that encounter killings are widely constituted as a form of ritual purification and social defense by self-sacrificing police, it theorizes a metaphysics of police vigilantism in India that combines generalized experiences of insecurity with shared cosmologies of just war. Comparing this metaphysics with justifications of state violence in other Global South contexts, this study sheds light on how such violence may be legitimated through the conceptual inextricability of law and war as embodied in a uniquely constituted human figure: the police vigilante.