Active Harmer Information (Active Shooter)




An Active Shooter is an individual actively engaged in killing or attempting to kill people in a confined and populated area. More recently, the term was updated to “Active Harmer” because, while the individual’s intention is the same, the weapon used may not be a firearm (e.g., hatchet, knife, vehicle, etc.)

Active harmer situations are unpredictable and evolve quickly. Typically, the immediate deployment of law enforcement is required to stop the person levying the attack and mitigate harm to victims.

Run Hide & Fight Poster


Quickly determine the most reasonable way to protect your own life. Remember that visitors are more likely to follow the lead of students, faculty, and staff during an active harmer situation. (Literature and established training programs reference and/or use the term, "Active Shooter." The difference between the two terms (Harmer vs. Shooter) is the weapon used in the commission of the incident).


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 law enforcement
  • Do not attempt to move wounded people
  • Call 9-1-1 when you are safe


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

  • Your hiding place should:
    • Be out of the active harmer's view
    • Provide protection if shots are fired in your direction (e.g., an office with a closed and locked door)
    • Not trap you or restrict your options for movement
  • To prevent an active harmer from entering your hiding place:
    • Lock the door
    • Blockade the door with heavy furniture
  • If the active harmer is nearby:
    • Lock the door
    • Silence your cellphone and other electronic devices
    • Turn off any source of noise (e.g., radio, television, etc.)
    • Hide behind large items (e.g., cabinets, desks, etc.)
    • Remain quiet
  • If evacuation and hiding are not possible:
    • Remain calm
    • Dial 9-1-1, 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


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

  • Acting as aggressively as possible against him/her
  • Throwing items and improvising weapons
  • Yelling
  • Committing to your actions


For additional information refer to the US Department of Homeland Security "Active Shooter: How to Respond" guide (.pdf)


  • Program the University Police Department's telephone number in your cellphone (AHEC/CU Denver 303-556-5000 & CU Anschutz 303-724-4444)
  • Ensure you are signed up to receive CU Alerts! (visit
  • Report suspicious behaviors to University Police, CARE Team or FaST
  • Be aware of your surroundings
  • Note the location of emergency wall phones, quick reference guides, and blue poles, etc.
  • Wear your University-issued badge
  • Add the Campus Emergency Information Line telephone number to your cellphone contacts (AHEC/CU Denver 1.877.556.EMER & CU Anschutz 877.INFO.070)

Active Harmer
Awareness Training

Due to COVID-19 precautions, in-person Active Harmer training has been suspended.  Once in-person trainings can take place, the dates, times, and locations of trainings will be posted here.