The state of California has one of the largest and most violent gang populations in the United States. Although there have been a variety of anti-gang measures and policies enacted by local and state governments, none have been more effective than the Civil Gang Injunction (CGI). This civil action prohibits certain street gangs, and their members, from participating in activities that would otherwise be considered lawful. In order to obtain an injunction a prosecutor must demonstrate to the court that the gang is engaged in ongoing criminal conduct and represents a public nuisance to a geographically defined area. When a neighborhood is under an injunction, not only is police presence in the area increased but officers are also given more freedom to investigate and apprehend gang members who are suspected to be in violation of the terms. As this thesis will argue, injunctions, when used correctly, have proven to be an effective weapon in diminishing the influence of territorial street gangs on community well-being. When used incorrectly, however, they often only provide a temporary fix to a long-lasting problem. They also have been known to contribute to an increase in crime in neighboring areas, an increased number of wrongful arrests, and in some cases they have promoted criminality amongst young people. To explore the efficacy of injunctions, this thesis will focus on three empirical studies that cover a period from 1993 to 2003, when the rates of gang-related violence were at an all-time high and injunctions became the primary tool for City and District Attorneys to combat the nuisance. Two of these studies argue that injunctions have a positive impact on violent crime statistics, whereas the third concludes that they do not. By comparing these conflicting pieces of quantitative evidence, this thesis aims to gauge the actual effect of injunctions on crime rates and weigh the perceived benefits of this measure against its unintended negative effects.