The Columbine tragedy on April 20, 1999 and other more recent shooter scenarios have led police agencies to reconsider what has been their traditional approach to these events. It has become increasingly apparent that a different strategy is needed to deal with Active Shooter Events (ASE), and that simply containing shooters is not an effective means to protect the public. Numerous ASE training programs have sprung up throughout the United States, yet to date, no set of best practices has emerged. This book fills this void, dispelling common myths about ASEs and providing a model for response.