School shootings, such as Columbine, have prompted police executives to explore response tactics and preparedness efforts for combating active shooters. This qualitative exploratory case study focused on specific preparation initiatives that have been implemented for the purpose of dealing with active shooters. Being prepared is one of the only ways to mitigate and properly counter some of these horrific acts that leave many children dead or wounded. Furthermore, preparation for active shooters is critical because the aftermath of such incidents may have additional long-term consequences, such as lawsuits, insurance settlements, and public scrutiny. Therefore, taking an interest in local law enforcement preparation tactics is essential. A qualitative exploratory case study of a purposefully selected law enforcement agency in Ohio, referred to as the Metropolitan Police Department (Agency MPD), was conducted for exploring this phenomenon. The methodology was designed to capture the most current snapshot of law enforcement preparation efforts. The selected agency consisted of sworn peace officers and was located in a large metropolitan area. The theoretical framework discussed tactics and preparation concepts currently discussed in law enforcement; however, many of these tactics were mere suggestions. This study identified preparation efforts by collecting data from written documentation, observations of active shooter training exercises, and interviews with law enforcement personnel having direct influence on active shooter preparation. A content analysis strategy was used to assess the unit of analysis as well as the data collected within that organization. Results indicated that Agency MPD has implemented numerous active shooter preparation tactics since the Columbine High School shooting. Efforts conducted by Agency MPD include threat assessments and crisis plans, school site surveys, multi-jurisdictional collaborations, school resource officers, practical training exercises, and tactical response protocols. Conclusions drawn from the research indicated that Agency MPD has not only implemented numerous preparation tactics, but continuously assessed and reevaluated their efforts as new tactics emerged. Additional active shooter research that explores other law enforcement agencies and compares preparation efforts is recommended. Although this research created a baseline for police preparedness, more research on police preparation is needed in an effort to compare or evaluate response effectiveness. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]