20 Active Shooter and Active Killer Prevention Strategies

These are the steps your organization should take to increase the chances that a planned attack will be averted.


Although there are no prevention strategies for active killer-types of attacks that have been proven to work 100 percent of the time, there are prevention approaches that are worth the effort they require. A number of these have been used to successfully avert mass casualty attacks, and some of these have been effective in preventing multiple attacks.

In every planned attack I have worked to date, the media reporting about the actual facts of the cases is likely to be inaccurate in many regards. Only the full case file will give us a reliable picture of what happened and what if any real opportunities there might have been to prevent these attacks. However, these types of case reviews often reveal at least some potential for interrupting large-scale attacks (see Active Killer Trends sidebar below).

While emergency preparedness efforts are especially important for situations where an active shooter or active killer incident cannot be prevented, it is my experience that it is unwise to spend more time, energy and budget on responding to these catastrophes than on trying to prevent them in the first place. This article will focus on potential strategies that can increase the chances that a planned attack will be prevented. A comprehensive approach using multiple strategies is more reliable than a focus on only one or two concepts.

1. Multi-disciplinary threat evaluation and management
Properly developed and implemented multi-disciplinary threat evaluation and management teams have demonstrated considerable success in preventing many planned school shootings, bombings and suicides since the technique was first used to stop a planned school shooting in the Bibb County, Ga., public school system more than 25 years ago. This is one of the most effective and reliable prevention strategies when the dangerous individual is part of the campus community. The law enforcement and mental health components of this approach are critical to a more accurate and actionable evaluation.

2. Visual weapons screening
This approach has also been used to successfully prevent a number of planned campus shootings. Visual weapons screening involves training personnel how to look for and recognize a variety of specific physical behaviors often exhibited by persons who are carrying a concealed weapon.

3. Pattern matching and recognition
This research-based approach is known by several other names and was used to help avert a planned shooting of a school bus more than two decades ago. Pattern matching and recognition involves training people to pay attention to patterns of human behavior that are incongruent for the time, setting and context of the situation. The often subtle behaviors can help staff detect potentially dangerous people regardless of the type of weapon they possess.

4. Anonymous reporting systems
Twenty-four-hour, 365-day per year anonymous tip/text reporting lines have been in use since at least 1990 and have helped campus officials avert numerous planned campus shootings, suicides and other deadly situations.

5. Banning potential violators from campus
Banning potentially dangerous persons from campus property combined with the arrest and search of violators who return can help campus officials interdict a potentially dangerous person before they can open fire. As one example, a planned school shooting was averted in Hinesville, Ga., when a school resource officer arrested three individuals who returned to the campus after he banned them earlier in the afternoon. When three guns were found in their possession, the suspects admitted they had come to the school to carry out a planned shooting.

6. Effective use of crime prevention through environmental design (CPTED) concepts
The proper utilization of CPTED can help improve the connectivity between people, the ability for building occupants to see a potential threat in time to react to it, can improve access control and can help to make more overt physical security measures less intimidating. The greater the need for physical security measures, the greater the impact CPTED can have.

7. Good physical perimeter security
Effective physical security can create significant delays and in some instances even barriers to an attacker. A stalker who had vowed to kill a Georgia primary school teacher was arrested by police after he repeatedly and unsuccessfully tried to defeat the school’s perimeter security. School district police officers recovered a loaded .32 caliber semi-automatic pistol from the man’s waistband. In addition to preventing some attacks, good physical perimeter security can make it more difficult for a potential attacker to surveil a campus to plan an attack.

8. Robust visitor screening and management
Today’s electronic visitor management systems are highly robust and can help prevent people who have been barred from the property from entering the main areas of a campus or building. For instance, using an ID badge or card similar to the types of identification that you can find here can ensure that only authorized individuals can gain access to the facilities and buildings on site. In schools, for example, ID cards have come a long way in recent years and should be administered to staff, students, and visitors. Like good perimeter security, properly utilized visitor management systems can make it more difficult for a potential attacker to conduct a detailed pre-attack survey.

9. Security and ballistic windows in key areas
A planned shooting was averted at a Minnesota elementary school through a combination of a prompt lockdown and the installation of security screen doors. When the police arrived, they observed the suspect beating on the glass of the front door trying to gain entry with a handgun. The security window film prevented him from entering the school. Installing something like Unbreakable Glass is a superb security tactic for any property and should be considered by anybody looking to protect their building from invasion.

10. Properly screened, trained and equipped security and law enforcement officers
While active shooter events have occurred on campuses with armed security and police officers on duty, there have also been a number of incidents that have been averted by armed officers in the campus setting. In addition, a number of active shooter events have been interrupted by armed officers.

11. Monitoring of social media
Though there are many challenges to this approach, there are sometimes opportunities to detect indications of impending danger via troubling social media posts. One school system likely averted a shooting when officers from the district’s school police department special operations unit confronted a former student who was posting frightening step-by-step plans for a hypothetical attack on his former high school. Considerable efforts are being made to develop effective and practical software solutions in this area.

12. Intelligence databases
A number of planned attacks by gang members have been detected and averted through multi-agency gang information databases. Increasingly, law enforcement agencies are using multi-agency databases to help monitor other types of potentially dangerous individuals and groups.

13. Internal and interagency information sharing
While software programs can be an invaluable tool to help multiple agencies detect and monitor potentially dangerous individuals in a region, old-fashioned collaboration and cooperation are still an important means for campus organizations and area law enforcement officials to identify and address potentially dangerous individuals.

14. Traffic enforcement
Officers Woodrow Telfair and Stephanie Prater prevented a planned gang shooting when they attempted to make a traffic stop on a city street adjacent to the Central High School Campus in Macon, Ga. When the suspects sped away, students in the area yelled to the officers that the car contained gang members who had just brandished a handgun and had stated that they were about to open fire. After a short chase, the three suspects were taken into custody by Telfair, Prater and backup officers. The department also recovered numerous firearms from convicted felons during traffic stops and license and insurance checkpoints near schools.

15. Proper background checks of employees and volunteers
Research by U.S. Postal Inspectors found that a number of individuals who carried out planned attacks in postal facilities had prior records and/or significant workplace behavioral issues prior to being hired that could have been caught by this Iowa background check or others, should they have been carried out. Improvements in screening applicants became part of USPS’ successful approach to preventing future acts of workplace violence.

16. Gun detection canines
In the past, gun detection canines have been successfully used to deter students and non-students from having firearms in their cars, in student lockers and hidden on campus grounds. In recent years, new training approaches have been developed that make it possible for officers to use canines to detect people in public settings who are carrying a firearm or an explosive device. Particularly helpful for large events such as concerts, athletic events and graduation ceremonies, these impressive canines can detect the scent trail left by a pedestrian as they walk.

17. Security cameras with facial recognition software
Security camera technology has been improving dramatically in recent years. Newer systems enable the photographs of persons of interest to be uploaded into the system, which can often detect the person in a crowd through facial recognition software. Though these systems have limitations, they can provide an additional layer of detection if photographs of a person who may pose a threat are available. For example, if a terminated employee who has been banned from the property attempts to enter the campus to attack former supervisors and/or colleagues, this type of system might be able to detect his or her presence on or near the campus.

18. License plate recognition cameras
Many campus organizations use tag cameras to record the license plates of all vehicles entering their roadways and parking areas. While these can be useful tools to identify an aggressor after the fact, systems that will alert security personnel when the license plate of a known potential violator enters the campus can provide early warning for certain types of attacks. For example, if a campus employee has received death threats from her ex-husband and he attempts to enter the campus to act on the threat, security personnel can receive an alert as soon as his vehicle enters the campus.

19. Entry point metal detection
While reliable entry point metal detection requires a number of supportive measures such as checkpoint security, screening of all hand carry items such as purses and good perimeter access control, it does provide levels of security that other countermeasures cannot create. Careful planning and penetration testing can help ensure a viable weapons screening approach.

20. Robust intrusion detection systems
The Ketchikan, Alaska, Police Department was able to prevent an active shooter event when they arrested a student who had broken into the school and climbed into the upper roof area. After responding officers checked the building due to multiple alarm activations, the department called in off-duty officers to conduct a more thorough search of the school and found the student who had a high-powered rifle equipped with a scope. The student told officers that he had planned to open fire on students when they gathered in front of the school in the morning.


While there are no foolproof methods to guarantee that active shooter and active killer events won’t take place in a particular setting, there are strategies that provide possibilities and probabilities that attacks can be averted. While there are other viable approaches that can be helpful in reducing the risks of active shooter attacks, these strategies are among the most practical for the majority of campus settings.

These strategies should be viewed as options to be considered rather than pass/fail items on a checklist that every campus organization should have in place. In addition, it is important to remember that each campus organization will be safer if it adopts a customized blend of strategies designed to fit local risks, realities and resources. Many planned campus attacks have been successfully thwarted using techniques described in this article.

Source: Campus Magazine Safety