An “active-shooter event” is not a new concern for citizens and law enforcement. These types of attacks go back many decades, but have become increasingly common and reported more frequently on a national level.

Over the last 20 years, law enforcement has been adjusting tactics and tools to better respond to active-shooter events. Many federal, state and local agencies have received training from the Advanced Law Enforcement Rapid Response Training program out of Texas State University.

Patrol officers receive advanced tactics and weapons training to “go to the sound of the gunfire” and stop the killing immediately. This puts them at great risk, but there is no time to wait for specialized teams like SWAT. Even with this preparation, the national average response time to an active-shooter event is about three minutes. To the potential victims at the scene, this time can be an eternity.

Law enforcement agencies are frequently requested by schools, businesses and community members for presentations on what they should do if confronted with an active shooter. The Civilian Response to Active Shooter Events course, designed and built on the “Avoid, Deny, Defend” strategy developed by ALERRT in 2004, provides strategies, guidance and a proven plan for survival.

Topics include the history of such incidents, the role of professional guardians, civilian response options, medical issues and drills. In 2014, Wal-Mart Stores Inc. introduced Avoid, Deny, Defend in a national awareness campaign for its more-than 1.3 million U.S. employees.

In August 2015, law enforcement officers from agencies across metro Atlanta attended the Civilian Response program at the FBI field office and were certified to pass on what they learned to citizens. The Marietta Police Department received more than 700 RSVPs for its Dec. 9 presentation of the course.

By its very nature, an active-shooter attack is usually a fast, sudden ambush. It is very difficult for anyone to react decisively or effectively in those first few seconds. However, once the shooting starts and the element of surprise is gone, the actions of people in the attack area can dramatically affect the number of those killed and injured.

• “Avoid” starts with your state of mind. Pay attention to your surroundings, and have an exit plan. Move away from the source of the threat as quickly as possible.

• “Deny” access while getting away may be difficult or even impossible. Keep distance between you and the source. Create barriers to prevent or slow down a threat. Turn lights off and remain out of sight and quiet by hiding behind large objects and silencing your phone.

• “Defend,” because you have the right to protect yourself. If you cannot avoid or deny, be prepared to defend yourself. Be aggressive and committed to your actions. Rally people around you to attack as a group and use improvised weapons if needed. Do not fight fairly; this is about survival.

When the police arrive, it is vital that you respond to the officers appropriately. Put down any weapons you may have and keep your hands visible unless otherwise ordered. Follow all commands, regardless of whether you think their commands are reasonable or not. For more information, go to: www.avoiddenydefend.org

When an armed robber or carjacker threatens someone and demands a wallet or car, the goal is generally to take your property for personal gain. Resistance “may” result in escalation of violence. An active shooter’s only goal is taking your life. There is no higher escalation of violence.

Just as the hijackings on Sept. 11, 2001 changed the way airline crews and passengers react to in-flight disturbances, we must recognize we can control the outcome of an active-shooter event. We cannot sit passively and hope for the best. Our actions can affect the outcome of the attack.

Brian Marshall is a lieutenant with the Marietta Police Department.