An active shooter is defined as an armed person who has used deadly force against individuals in the vicinity, who continues to use deadly force, and has unrestricted access to more victims. When an active shooter is in your vicinity, the most reasonable way to protect yourself is to evacuate, if possible. Determine an escape route, leave any possessions behind, and keep your hands visible.
If evacuation is not possible without endangering yourself further, quickly find a place to hide out of the active shooter's view. Lock the doors or block the entrance to your hiding place. Take action against the active shooter only as a last resort if your life is in immediate danger. Try to incapacitate or overwhelm the active shooter. In all cases, call 911 as soon as it is safe to make the call.
About Chris Grollnek: Mr. Grollnek, an experienced security and law enforcement professional, is a co-founder of Countermeasure Consulting Group, LLC. He is also experienced in consulting for victims and lawyers representing clients and victims of malicious prosecutions. For more information, please see www.chrisgrollnek.com.