Although there is an abundance of research examining the influence of structural conditions on total homicides, less is known about the differential influence of structural conditions on homicides disaggregated by type. Justifiable homicide by civilians represents one type of homicide that has received little attention in the literature, particularly at the macro level. Given the debate about the role of guns in cases of self-defense, it is clear that this category of homicide is important to study for theoretical and practical reasons. The authors provide an empirical assessment of these issues using data from 188 U.S. cities with populations of more than 100,000. The findings indicate that cities with higher rates of violence, with more divorced men, and located in states with less restrictive gun laws on concealable firearms have higher rates of justifiable homicide. In addition, as cities increase the level of police per capita, justifiable homicide rates are significantly lowered. The implications of these findings for theory and policy are discussed.