This chapter explores the problem of active shooter violence and suggests how first responder training might be employed as an effective response to such events. In so doing, we first take a look at why we believe the need for this training exists. Beyond the need for first responder police training that has been underscored by recent high-profile events, we next examine what we think officers might need to know to be better prepared in the future. The last part of this chapter presents a model that has been developed in Texas to address the problem of active shooter violence. While data currently are being collected to determine the utility of this training, we believe that the approach described here offers a systematic method that will prepare uniformed law enforcement personnel for dangerous situations that they may see more of in the future. Accordingly, this chapter is unique because rather than addressing a specific problem in any single jurisdiction, it addresses a general challenge that law enforcement agencies must face regarding training officers to be able to respond appropriately to the threat of a very serious problem that could occur in any jurisdiction at any time.