“When Stephen Paddock began firing on concert attendees at the Route 91 Harvest Festival
in Las Vegas, police were initially unable to pinpoint his exact location. [Emphasis mine] The
gunfire was most definitely coming from somewhere in or near the Mandalay Bay luxury resort and casino, which is
across the Las Vegas Strip from the festival grounds, but the resulting chaos made determining Paddack’s vantage
a problem. According to CBS News, when police eventually did figure out where the suspect was located, it wasn’t
due to eyewitness accounts of muzzle flashes. Rather, he was found thanks to his hotel room’s smoke
detector.” (Ref. 1)
From all reports to date, security at the site of the concert were well planned and
implemented. The sniper attack from around 400 feet above the venue of the concert and nearly a quarter of a mile
away made if essentially impossible to defend against. Still, one of the questions that will be asked in the coming
days is: Could the attacker have been located much more quickly, thereby allowing law enforcement and
security to quickly and accurately return fire, either killing the attacker, or, at the least, disrupting his aim
so that fewer people would have fallen victim to the murderous attacker?
The answer to this question is yes. Over the past decades, military and law enforcement
agencies have developed the needed technologies to accomplish this task and systems to quickly and accurately
locate snipers are available today. While such systems are expensive, they could be rented out to concert promoters
or sponsors of similar events to be used as part of the normal security measures deployed during events with large
numbers of attendees. The cost of renting such a system for a weekend would be quite nominal.
A gunfire location system is one that typically detects and locates the source of gunfire
using acoustic and optical sensors. Most of these systems possess three main components: 1) An array of microphones
and/or optical sensors; 2) A computer processing unit; and 3) An operator-display to tell, in near real-time, from
where the gunfire is originating.
Modern acoustic detection systems use arrays of microphones to detect and locate the
source of gunfire. An example of this technology is the Boomerang system, developed by DARPA (Defense
Advanced Research Projects Agency) and BBN Technologies. Boomerang works in extreme weather, in open fields and in
urban environments, whether stationary or moving. Stationary Boomerang units were utilized in the "Athletes'
Village", at the starting line, and finish line areas of the 118th running of The Boston Marathon in 2014 as a
result of the 2013 bombings that took place at the finish
Modern optical or electro-optical systems can detect the muzzle flash of a firearm. Such
systems require that they have a line of sight to the weapon being fired. Nearly all of these electro-optical
systems employ either infrared or ultraviolet sensors and they have seen increasing success in military environments
where immediacy of response is critical. As with acoustic systems that require more than one microphone to locate
gunshots, most electro-optical systems require more than one sensor when covering 360 degrees. Acoustic and optical
sensors can be co-located and their data can be fused thereby providing a very high degree of gunfire location
accuracy. Such systems can easily declare and locate even multiple sources of gunfire. This integration of acoustic
and optical sensors assists in overcoming each system's own limitations while improving the overall capability to
eliminate false alarms. Optical and acoustic sensor systems have been used at stationery ground sites, from vehicles
on the move in urban and rural environments, as well as on airborne and waterborne
Years ago, as part of my engineering career, I had the opportunity to work on several
weapon detection/location systems for both military and law enforcement applications. Several of these systems
were electro-optical airborne and vehicle-mounted (tank and armored vehicle) missile warning systems, some of which
have been successfully protecting our military’s helicopters and aircraft against surprise missile
Back in the late 1960s, during the Vietnam war, U.S. marines manned a combat base at Con
Thien located near the Vietnamese Demilitarized Zone, about 2 miles from North Vietnam. It was the site of fierce
fighting from February 1967 through February 1968 with heavy North Vietnamese artillery fire falling on the Marine
positions. To counter the enemy artillery, a gunfire location system called Firewatch, consisting of an
acoustic array, an infrared flash location system and high powered visual optics, was deployed at Con Thien that
could accurately and quickly locate the enemy weapon, allowing counterfire to destroy the artillery piece before
it could be moved to a new location.
In the 1990s, a prototype acoustic/electro-optical sniper detection/location system was
tested at the Military Operations on Urban Terrain (MOUT) facility at Camp Pendleton in California. The MOUT
facility allowed testing of the sniper detection/location system in an environment that replicated urban
environments in which military units might find themselves when deployed in support of foreign operations. The
Camp Pendleton MOUT training complex was configured to allow up to platoon size units to conduct foot, mobile,
and limited motorized patrols around and in the training
Acoustic gunfire detection systems have been in use for several years by police departments
here in the U.S. For example: “In October 2007, the Boston Police Department went live with ShotSpotter,
an acoustical technology that provides an immediate notification when shots have been fired. Since then a network
of electronic ears has been monitoring some of Boston’s high-crime neighborhoods, listening for the telltale sounds
of gunfire.” (Ref. 5)
For hundreds of years, people wanting to know how far away the lightning in a thunderstorm
was, would see the lightning flash and then count off the seconds till they heard the boom of thunder – each second
corresponding to about 1100 feet in distance. This method of estimating range to the lightning stroke is called
The flash-bang technique, using one’s eyes and ears, has been utilized for hundreds of
years to locate and range on enemy artillery. As an artillery officer, Napoleon Bonaparte would have used
flash-bang ranging to coordinate return fire against enemy cannons. An artillery spotter would see the
flash of the enemy’s cannon, thus localizing the angle to the weapon and then wait for the sound of the cannon’s
firing, which would allow for an estimate of range to the weapon.
The Flash-bang artillery location technique was improved prior to World War I with the use
of stop-watches. Stop-watch methods involved spotting a gun flash, measuring the bearing to it and the length of
time it took the sound to arrive.
Today’s technologies can provide very accurate gunfire location accuracy compared to that
of Napoleon’s time. Modern infrared optical sensors can locate gun flashes to angular accuracies of small fractions
of a degree, while flash-bang ranging can produce accuracies on the order of several feet. The computer-aided
detection and location process today can be performed in as little as a second or less. A complete gunfire location
system, with an array of acoustic and optical sensors, can provide complete hemispherical coverage, i.e., full
360-degree horizontal coverage and 90-degree vertical coverage. Mounting a gunfire location system on a small raised
platform would provide a clear view of surroundings at public events similar to the one where the mass shooting
took place in Las Vegas. The rapid and accurate shooter location provided by such a system could
result in far fewer casualties and the quicker neutralization of the sniper. Accurately locating a sniper within
a second after his first shot could allow a skilled marksman to immediately return fire. While the return fire
might not actually hit the sniper, it would almost certainly cause him to pause and/or take cover, thereby reducing
the number of rounds he could fire and disrupting his aim – all of which would contribute to lowering the casualty
Another approach to countering the sniper threat after the source of the shooting has been
determined, is the use of one or more non-lethal techniques that have been developed and tested over the years by
the military. One proven and effective method is that of shining a high-powered light source at the sniper. This
causes the person looking at the light to blink, to lose optical focus, to turn his head away from the light or
even to cause temporary visual degradation of loss of vision. Such methods reduce the potential of injuring
innocent bystanders and increase the chances of capturing the shooter and subsequently interrogating the person.
Using accurate positional information from the gunfire location system permits the high-power illumination system
to confine the light to a narrow beam focused upon the shooter’s location.
So, while the Las Vegas shootings have shown that the threat from terrorists, lone wolfs,
deranged individuals, or others has escalated, there are means available to counter this increased
threat. There are lessons to be learned from Las Vegas and it is almost certain that as a result of these lessons
learned, new and improved security techniques, equipement, and procedures at public events will be
- Las Vegas Police Were Able To Find The Shooter Thanks To The Mandalay Bay’s Smoke Detectors,
Andrew Husband, UPROXX, 2 October 2017.
- Boomerang (countermeasure), Wikepedia, Accessed 5 October 2017.
- Gunfire Locator - Design - Sensing Method - Optical, Delores Handy, liquisearch.com,
Accessed 5 October 2017.
- Uncooled infrared sensors for an integrated sniper location system, Timothy J. Spera and
Burton D. Figler, Proc. SPIE 2938, No.326, 18 February 1997.
- Surveillance Technology Helps Boston Police Find Location Of Gunfire, Delores Handy,
WBUR News, 23 December 2011.