Prior research has applied risk assessment and spatial analysis techniques to the study of violence. This paper builds on those results, tying the practical outcomes of spatial risk analysis methods to broader spatial issues on the articulation of risky places for aggravated assault. We begin by conceptualizing key relationships, addressing the effects of environmental factors on creating distinct, identifiable areas that are conducive to crime. Propositions of the theory of risky places are posed and then empirically tested using a GIS based program, RTMDx, on aggravated assault data in an urban area. Given the current thinking about crime vulnerability based on concentration and spatial influence of features and events, this paper offers an analytical strategy to model risky places that combines the conceptual insights of crime emergence and persistence, advances in geo-spatial analytical techniques, and micro-level data.