Following the 1999 Columbine High School shooting, it was hypothesized that offenders used knowledge gained from news media reports about previous events to plan mass shootings. Although researchers have studied active shooter events, little research has been conducted on the factors that influence an active shooter's decision and ability to carry out such events. The purpose of this study was to evaluate the relationship between the rate of news media reporting about an active shooter event and the casualty rate of the ensuing event in the United States. The bracketed time of this assessment was between April 20, 1999, and June 15, 2016. The age and regional location of the subsequent shooters were examined as moderating variables. Social learning and social cognitive theories constituted the theoretical framework. Data were gathered from existing mass shooting and active shooter studies, Google News, and the ProQuest Central database. A Spearman's correlation analysis revealed no significant relationship between the rate of news media reporting about an active shooter event and the casualty rate of the ensuing event. The age and regional location of subsequent shooters were not moderating variables. However, a Spearman's correlation analyses did reveal a significant relationship between the casualty rate of an active shooter event and the amount of news media coverage the event received prior to the ensuing event. The study finding clarified the need for active shooter reporting guidelines, similar to existing suicide reporting guidelines. The implementation of such guidelines could reduce the regularity and severity of active shooter events, thereby improving public safety in the United States by reducing the regularity and severity of active shooter events.