Confronting Active Shooters
Five tips for implementing shot detection technology
- By Thomas W. Connell II
- October 01, 2019
According to a recent report from the DOJ and FBI,
there were 27 active shooter incidents in the United
States in 2018, resulting in 85 deaths and 128 injuries.
Of these incidents, 16 occurred in business
environments, five occurred in educational buildings
and two occurred in healthcare facilities.
These situations are differentiated from other gun-related situations
because the FBI recognizes that in an active shooter situation,
law enforcement and citizens have the potential to affect the outcome
based on their responses. To aid law enforcement response and help
reduce the impact of incidents, security and life safety technology
providers have recently started offering gunshot detection systems.
Today’s schools, businesses and healthcare campuses are employing
indoor shot detection to reduce or eliminate delays and errors
common in victim- or witness-initiated responses to active shooter
incidents. Adding this technology to a campus life safety system can
help shorten the duration of an active shooter event.
While an active shooter incident is something that everyone hopes
never occurs, all campuses should have a response plan and the technology
to deal with the situation appropriately and quickly. In order
to select and implement the most suitable technology for a building
or campus, it is important to consider the following five suggestions.
1. Choose the System Most Appropriate for Your Building Layout
Some shot detection systems use single-factor acoustic verification to
detect gunshots. Acoustic detection uses sensors to capture a sound.
Then, it develops an acoustic signature and uses computer-based signal
processing to validate if the sound is a gunshot. This data is then
used to determine the precise location of the shot.
Other systems use multi-factor authentication, where two or more
sensing technologies are grouped together. These technologies can
include the acoustic signature from a muzzle blast and/or from the
shockwave of a bullet passing through the sensor field, changes in
barometric pressure triggered by a shockwave, an optical flash/infrared
signature from the ignition of explosive gasses in the ammunition
propellant and comparison of the acoustic signature against an audio
library of previously recorded gunshots.
Unfortunately, multi-factor authentication can fail to recognize an
active shooter event if one type of detection is not authenticated due
to the configuration of the space. For example, if an active shooter
system requires both acoustic and muzzle flash authentication, wall
sensors will pick up the gunshot, but muzzle flash may be masked by
partitions or walls separating cubicles, offices or classrooms. While
acoustic sensors can detect sound through walls and corners, infrared
sensors can only pick up flashes within its line of sight.
2. Understand the Potential for False Alarms
The goal of multi-factor authentication is to reduce the number of
false alarms by providing dual—or even triple—sound authentication.
However, it can be a costlier solution because more sensors may
need to be used. There is always the potential for false alarms regardless
of the technology employed. There are single-factor systems with
a lower false alarm frequency than some multi-factor systems in the
marketplace today. It’s important to discuss the potential with the
system providers and ask them how, and against what conditions and
catalysts, their systems have been tested.
With single-factor acoustic detection, computer-based signal processing
helps increase precision by analyzing a sound to determine if
it’s an actual gunshot or just another sound with similar characteristics.
For example, a cymbal crash from a drum set, which could be
found in the music department of many campuses, has been found to
trigger false alarms. Ongoing testing allows developers to refine algorithms
and rule out these potential false alarms.
It is also important to consider that not every false alarm is necessarily
a bad thing. In fact, it is arguably preferable to react to a false
alarm than to have a system fail to identify an actual gunshot.
3. Know Best Practices for Sensor Placement
Acoustic sensors are most frequently mounted in ceilings or on walls.
The range of sensors varies by manufacturer and depends on the
acoustical characteristics in the space, like reverberation and sound
absorption properties. Even the shooter’s body can create an acoustic
shadow when shooting forward with their back facing the sensor.
While there is no limit to the number of sensors that can be placed
throughout a building, budget concerns are forcing campus facility
managers to focus their investment on placing sensors only in potentially
Some recommend placing sensors in areas where large numbers of
people congregate like cafeterias, gymnasiums or auditoriums. However,
this is not necessarily where the first shots take place. Other
variables, including building access, approach, motive and the shooter's
actions all play into the location of the first shots. Entryways and
hallways may be the most effective areas to detect first shots.
It is important to note that system design will never be able to
cover 100 percent of a building. This technology should be part of a
comprehensive campus safety plan developed by security professionals.
When determining what system will best fit your requirements,
ensure the technology provider gives you a clear system design illustrating
areas of coverage. Above all, involve your local law enforcement
and stakeholder emergency response agencies in the decisionmaking
4. Pick System Offering Communication with First Responders
Active shooter events present numerous challenges for first responders
and emergency staff. Communication of escalating events
between 911 and witnesses can be both confusing and erratic, which can delay on-site response. This is compounded
by the fact that active shooters can
move at a fast pace throughout the building—
making it even more difficult to track
the shooter and prolonging the event.
Early detection can trigger a host of
responses including alerting students, staff,
patients and other building occupants to the
location where shots were fired while triggering
building alarms, emergency notifications,
evacuation and sheltering procedures.
Recent tests have shown that shot detection
technology with automatic emergency
communication enables law enforcement to
respond and mitigate a threat up to 60 percent
faster. Today’s leading gunshot detection
systems even offer map-based graphical
user interfaces that display the location of
the shooter to building occupants and law
enforcement, as well as display audio and
video of the incident. The systems provide
safety and evacuation instructions while
communicating with emergency services
and mass notification systems, prompting a
quick response by law enforcement.
Acoustic detection can also indicate the
number of shots fired and the cadence at
which they were released, giving insight into
the type of weapon the shooter is using. This
data is sent to security, law enforcement,
hospitals and fire service to enhance their
overall strategic picture of the situation and
aid in response.
5. Look for Integration Features
To maximize effectiveness, it is important to
select a gunshot detection system that supports
multiple integration options, including
video feeds from existing CCTV and intrusion
systems, mass notification systems,
access control systems and panic button/
manual initiation systems.
In the future, the integration of shot
detection into existing life safety systems will
enable facilities to leverage the infrastructure
already in place. After detection occurs, mass
notification to occupants, first responders
and law enforcement can be sent through the
same systems used for fire detection. Like all
life safety systems, redundancies will be built
into shot detection technology to ensure
While no technology or planning will ever
eliminate active shooter threats, it can significantly
shorten the duration and lessen
the impact of the event. Advancements in
shot detection give occupants, emergency
management and first responders valuable
seconds to react to active shooter events and,
in turn, potentially save lives.
This article originally appeared in the September/October 2019 issue of Campus Security & Life Safety.