Planning and Response to an Active Shooter: An Interagency Security Committee Policy and Best Practices Guide [open pdf - 2MB]
"The primary mission of the ISC [Interagency Security Committee] Active Shooter Working Group is to streamline existing ISC documents on active shooter into one cohesive policy and guidance document that agencies housed in Federal facilities can use as a reference to enhance prevention, protection, mitigation, response, and recovery efforts related to an active shooter incident. The goal of the ISC's Active Shooter Working Group is to promote the highest chance of victim and responder survivability through awareness, prevention, education, and training. This guidance is designed to be applicable to all buildings and facilities in the United States occupied by Federal employees. These include existing buildings, new construction, or major modernizations; facilities owned, or being purchased, or leased; stand-alone facilities; Federal campuses; where appropriate, individual facilities on Federal campuses; and special-use facilities."
Department of Homeland Security: http://www.dhs.gov/