On July 20 this year, a gunman dressed in tactical clothing set off tear gas grenades and shot into the audience at a movie theater in Aurora, Colorado, killing 12 people and injuring 58 others. This tragedy reminds us that active shooter threats not only persist but have grown in prevalence in recent years. One of the most valuable resources available to assist local law enforcement against active shooters is an aware and educated citizenry. For this reason, the U.S. Department of Homeland Security (DHS) is committed to empowering citizens to be prepared and ready to react to an active shooter incident while strengthening capabilities within state and local law enforcement communities.