http://www.dhs.gov/video/options-consideration-active-shooter-preparedness-video

The Department of Homeland Security has compiled the following information on how to identify and respond if you find yourself in a situation involving an active shooter:

Profile of an Active Shooter

An active shooter is an individual actively engaged in killing or attempting to kill people in a confined and populated area, typically through the use of firearms.

Coping with an Active Shooter Situation

• Be aware of your environment and any possible dangers.
• Take note of the two nearest exits in any facility you visit.
• If you are in an office [or classroom], stay there and secure the door.
• If you are in a hallway, get into a room and secure the door
• As a last resort, attempt to take the active shooter down.  When the shooter is at close range and you cannot flee, your chance of survival is much greater if you try to incapacitate him/her.

How to Respond When an Active Shooter is in Your Area

1. EVACUATE

If there is an accessible escape path, attempt to evacuate the premises.  Be sure to:

• Have an escape route and plan in mind
• Evacuate regardless of whether others agree to follow
• Leave your belongings behind
• Help others escape, if possible
• Prevent individuals from entering an area where the active shooter may be
• Keep your hands visible
• Follow the instructions of any police officers
• Do not attempt to move wounded people
• Call 911 when it is safe to do so

2. HIDE OUT

If evacuation is not possible, find a place to hide where the active shooter is less likely to find you. 

Your hiding place should:

• Be out of the active shooter's view
• Provide protection if shots are fired in your direction (i.e. an office with a closed and locked door)
• Not trap you or restrict your options for movement.

When hiding you should:

• Lock the door
• Blockade the door with heavy furniture
• Silence your cell phone and/or pager
• Turn off any source of noise (i.e., radios, televisions)
• Hide behind large items (i.e., cabinets, desks)
• Remain quiet.

If evacuation and hiding out are not possible:

• Remain calm
• Dial 911, if possible, to alert police to the active shooter's location
• If you cannot speak, leave the line open and allow the dispatcher to listen

3. TAKE ACTION against the active shooter

As a last resort, and only when your life is in imminent danger, attempt to disrupt and/or incapacitate the active shooter:

• Act as aggressively as possible against him/her
• Throw items and improvise weapons
• Yell
• Commit to your actions

How to Respond When Law Enforcement Arrives

Law enforcement's purpose is to stop the active shooter as soon as possible.  Officers will proceed directly to the area in which the last shots were heard.

• Officers usually will arrive in teams of four (4)
• Officers may wear regular patrol uniforms or external bulletproof vests, Kevlar helmets, and other tactical equipment
• Officers may be armed with rifles, shotguns, handguns
• Officers may use pepper spray or tear gas to control the situation
• Officers may shout commands and may push individuals to the ground for their safety

When officers arrive:

• Remain calm and follow officers' instructions
• Put down any items in your hands (i.e. bags, jackets)
• Immediately raise hands and spread fingers
• Keep hands visible at all times
• Avoid making quick movements toward officers such as holding on to them for safety
• Avoid pointing, screaming, and/or yelling
• Do not stop to ask officers for help or direction when evacuating, just proceed in the direction from which the officers are entering the premises

Information to provide law enforcement

• Location of the active shooter
• Number of shooters, if more than one
• Physical description of the shooter(s)
• Number and type of weapons held by the shooter(s)
• Number of potential victims at the location