The ShotSpotter Gunshot Location System

Frequently Asked Questions

Does my city need the ShotSpotter Gunshot Location System (GLS)?

Police nationwide think the answer is a resounding “yes.” Customers have seen reductions in gunfire rates by 50-80% in areas where the ShotSpotter GLS has been deployed for more than a year, and it continues to keep cities safe in every single location in which it has been installed. (ShotSpotter has the only 100% acceptance-and-operational record in the industry.)

One of the safest counties in America (Nassau, NY) chose to deploy the ShotSpotter GLS to address higher incidents of gunfire in select areas. In communities where gunfire is not a daily problem, the ShotSpotter GLS can help get emergency care to victims. In 2004, Jane Doe was shot in the neck in Arizona city. No one heard the gunshot and no one called for police or paramedics, but ShotSpotter did so, help arrived and Ms. Doe has completely recovered.

Is gunfire really a problem these days?

Absolutely. Despite remarkable progress in law enforcement and decreasing crime rates throughout the ’90s, in 2002 (the most recent year for which figures are available), the FBI reported some 18,000 homicides nationwide, of which 12,000 involved the use of a gun. That’s 33 homicides involving guns per day, or a little more than one every forty-four minutes. And these figures do not include attempted homicides, of which there are, by some estimates, perhaps five to six times as many.

Homicide-related gunfire is not the only reason for the illegal discharge of weapons. Around the country, otherwise law-abiding citizens fire guns into the air in celebration around certain holidays. Unfortunately, following the old dictum that “what goes up must come down,” those citizens often don’t realize that the bullets they fire up can, and have, come down only to kill people miles away. Through the extensive use of ShotSpotter systems, targeted publicity and careful follow-up after periods of high gunfire activities, police have been successful in virtually eliminating “celebratory gunfire” in cities which have had the ShotSpotter GLS the longest.

What is the cost of gunfire?

There are very real costs—both financial and in terms of police officers’ health and safety—of gunfire, even if they are not immediately obvious. In fact, in 2003, the Chicago Sun Times estimated the cost of every gunshot victim to society at approximately $170,000, including medical costs, investigation, prosecution, and legal costs. (This cost did not include the cost of criminal incarceration.) And these figures do not account for the costs to local businesses of the climate of fear which develops within communities plagued by gun violence. By helping to eliminate gunfire, and to put criminals in jail who will not cease firing guns despite the installation of ShotSpotter systems, we help mitigate these and many other related costs, thereby keeping more funds and resources available to citizens for other municipal and civic purposes.

What about my privacy?

Privacy rights are an issue of utmost importance to ShotSpotter. We have spent tremendous time and effort designing our gunshot location systems in order to ensure the privacy rights of every citizen. Our sensors trigger only when a loud, impulsive sound is detected. Impulsive noises are defined as the short, rapid onset, high intensity sound produced by a discharge of a firearm, firecracker, or explosion. Human speech is incapable of producing such sounds; hence our sensors are unable to be triggered by either the human voice or many other loud noises such as train whistles, loud vehicles, jet engines, dog barking, etc.

When an impulsive sound occurs-such as gunfire, a firework, or an explosion noise-- and meets these criteria, our system automatically downloads a brief audio clip of the incident. The audio clip lasts only a few seconds and usually starts a few seconds before the sound and ends a few seconds after. Incident audio is immediately is sent to personnel responding to the alert, allowing them to make an accurate assessment of the incident. For example, a police dispatcher listening to an incident audio clip would be able to immediately hear whether one or multiple guns are being fired. Such information gives critical situational awareness to first responders who might otherwise arrive at the scene of a highly dangerous situation without proper preparation.

In extremely rare cases, the sounds of loud human voices can be heard in the background after an impulsive incident has triggered our system. In all of these cases, only the sound of voices can be heard, not the actual words. This is because sensors are typically deployed on building rooftops, far off the ground and away from public access. In short, we deploy our sensors are too far away. This is a part of our patented spatial filtering process. In fact, typical human speech is not intelligible at distances greater than twenty feet away from our acoustic sensors as we use the same microphones used in most cell phones. Try this experiment yourself: while outdoors, call your own voicemail using your cell phone, set your phone down, walk twenty to thirty feet away and speak in a normal voice. When you play back the voicemail, your speech will not be intelligible.

How do you protect my privacy?

We've gone to great lengths to ensure that our technology cannot be used to eavesdrop and invade privacy. Despite misinformation, there is no “listen live” feature in our wireless sensors for two reasons: (1) we are dedicated to preserving personal privacy (2) ShotSpotter sensors are deployed on relatively low bandwidth networks which could not sustain continuous transmission of audio. In short, such a feature would swamp and crash our wireless network. We intentionally implemented this design limitation to ensure privacy and keep system costs down.

Why is ShotSpotter the market leader?

For two simple reasons: First, no other company requires fewer sensors per square mile than ShotSpotter. Our patents prohibit anyone from deploying systems with fewer than 25 sensors per square mile, while our experience proves that sensor densities of 20 per square mile are optimal. Second, no other company can offer the real-world experience and reputation ShotSpotter has. Every single one of ShotSpotter’s customers has kept its system installed, several have expanded after initial installation, and every single one of our accounts is a reference for our experience and dedication.

Other systems claim they only need one sensor to detect gunfire — how many do you require?

Don’t be fooled by this misleading statement! While other systems may be able to locate nearby gunfire with only 1 sensor, those systems cannot locate gunfire at the 1.5 to 2 mile distances the ShotSpotter GLS can. Systems which detect gunfire based on its closeness to a given sensor are called proximity detection systems. They have narrow applicability—when there is advance knowledge of shooter’s location and intended firing direction. Expect proximity detection systems to work within a very limited area—a circle with a 200 or 300 foot radius. Assuming a generous 250-foot detection radius, a proximity detection system would require between 100-450 sensors to provide the same coverage as the ShotSpotter GLS would with 10 to 15 sensors.

Moreover, with proximity detection systems, operators know only that an event took place “nearby” and sometimes “in that direction.” By contrast, the ShotSpotter GLS provides precise latitude and longitude (as well as street address) for every single detected incident.

How long does it take to deploy a ShotSpotter system?

Using the ShotSpotter Rapid Deployment Wireless Gunshot Location System, customers can deploy a tactical use or temporary ShotSpotter system within a few hours. For longer-term deployments, wireless systems take approximately four to five hours to install, per sensor, while wired systems require a few weeks’ lead-time but require less than two hours per sensors to install.

Is the ShotSpotter system difficult to use?

ShotSpotter has police dispatch professionals, former sworn law enforcement professionals on staff who provide training. System training is included in the cost of every system, and regular “refresher” training is offered.

Typically, no more than two hours’ training is required for dispatchers and other personnel to learn to use the system for basic incident detection, dispatch, and recording functions. For more detailed forensic analysis and reporting, investigators and detectives generally require an additional four to six hours training, depending on their existing forensic and scientific background.

Couldn’t this money be better spent hiring more police?

ShotSpotter systems are not a replacement for the hard work of law enforcement professionals. ShotSpotter GLS is generally acquired through separate funding streams than the operational budgets that pay police salaries.

Since the ShotSpotter GLS classifies impulse sounds as threatening or non-threatening (e.g. fireworks, motorcycles), agencies will save time and money by not deploying personnel to "false alarms". The ShotSpotter GLS also helps Investigators and Detectives save time collecting forensic evidence for building cases.

What about officer safety?

The ShotSpotter GLS is proven to increase officer safety. With the increasing incidence of the use of assault weapons (AK-47s and others), the ShotSpotter GLS’s automatic analysis of weapon events helps officers plan for the sorts of circumstances into which they will be entering when they respond to a call. By providing live audio playback of events to dispatchers or to investigators in the field, the ShotSpotter GLS allows officers to know what they are responding to before they arrive. And since being prepared is the best defense against injury to suspects or responding officers, the ShotSpotter GLS helps keep both officers and the suspects they are pursuing safer.

Is the ShotSpotter GLS a counter-sniper system?

The ShotSpotter GLS was deployed by the FBI over 90 linear miles of Ohio interstate highways during the 2003-2004 Ohio Sniper incident, in the largest deployment of gunfire location systems in the world. During that period, we provided key forensic evidence to the investigative team and were instrumental in collecting the evidence which eventually lead to his arrest. The ShotSpotter GLS is thus the perfect tool to combat domestic sniper terrorism.

Note: in the military world, counter-sniper systems have different meanings than they do in law enforcement.

What about court cases? Does the evidence hold up?

Because the evidence can be so compelling, data collected by ShotSpotter is regularly used by police to elicit confessions from suspects in homicide and other gunfire-related investigations. Thus, ShotSpotter evidence rarely makes it into contested trials because suspects have long before confessed in light of the evidence. However, should it be necessary ShotSpotter can provide expert witness testimony upon request for customers. ShotSpotter has a standing commitment to law enforcement and prosecutors to support their efforts in any way they can.

For additional information, please see: Case Study : Los Angeles County, CA - ShotSpotter Forensic Evidence Assists in Conviction (PDF)

How do you know it’s accurate?

The ShotSpotter GLS was tested and proven to be accurate by the National Institute of Justice back in 1998. That testing showed overall accuracy of 40 feet over a one square mile coverage area. In the years since 1998, ShotSpotter has produced numerous product improvements, increased system accuracy, and decrease false alarm rates.

But the best test of all is to ask ShotSpotter customers. ShotSpotter has collected some of what they have to say here, but you are also encouraged to ask department representatives in cities which have deployed the ShotSpotter GLS. Ask them, for example, what has happened to their “brass recovery rate” (the percentage of times officers responding to a shots-fired call actually recover shell casings). That number will have gone up, both because of a reduction in false alarms and because the ShotSpotter GLS provides precise locations of events for which locations were previously only known by the most approximate of measures. The ShotSpotter GLS has helped catch criminals nationwide, and police who have used it will tell you that once they have it, they never want to lose it, which is why ShotSpotter has never had to remove or decommission a system.