Gunshot Detection: What the Data Really Shows

Estimated reading time: 7 minutes

Late one night, a single gunshot echoes through a quiet neighborhood. No one calls 911. By the time officers arrive, the scene is cold with no witnesses, no shell casings, no answers.

So, when the department hears about gunshot detection technology (GDT), they see potential. The idea is simple but powerful: sensors placed across the city that can detect the sound of gunfire, pinpoint its location, and send an alert to officers within seconds. Faster responses, more evidence collected, and maybe, just maybe, an opportunity to stop the cycle of gun violence before it escalates.

After months of planning, the department launches a pilot program. Officers start responding to alerts, collecting shell casings, and sometimes arriving at scenes before anyone’s even called 911. Progress seems real.

But a bigger question remains: is this technology actually reducing gun violence, or is it just changing how officers respond? That’s what a team of researchers set out to answer in a rigorous study of Kansas City’s experience with GDT.

What Is Gunshot Detection Technology Supposed to Do?

Gunshot detection systems, like SoundThinking’s ShotSpotter, deploy sensors that can detect muzzle blasts or the sonic boom of bullets traveling through the air. Using triangulation, the system estimates the location of gunfire and sends an alert to dispatch with precise coordinates, often within seconds.

The promise is simple: faster responses, more evidence collection, and ultimately, less gun violence.

But the evidence so far has been… complicated. More than 250 agencies across the U.S. have adopted GDT, yet very few studies have rigorously evaluated whether it actually works as intended.

A Rigorous Test in Kansas City

Researchers Eric Piza, David Hatten, George Mohler, Jeremy Carter, and Jisoo Cho conducted an evaluation of Kansas City’s experience with GDT. Their study offers one of the clearest looks yet at what agencies can realistically expect from this kind of investment.

Kansas City installed its ShotSpotter system in 2012, covering about 3.5 square miles. Over seven years, the system detected 11,517 gunfire events. That’s a lot of data to work with so the researchers used a microsynthetic control method, a sophisticated approach that allowed them to create a near-perfect comparison group of similar street segments across the city.

In simple terms: they didn’t just look at before-and-after numbers. They built a statistical “twin” of the GDT areas as a control, matching trends over 13 years of data to isolate the effect of the technology as accurately as possible.

So, What Did They Find?

The good news first:

• More evidence collection. The GDT areas saw about 30% more ballistic evidence (NIBIN entries) compared to similar areas without GDT.
• More gun recoveries. Officers found more illegal guns, particularly in areas just outside the GDT zones.
• Fewer shots fired calls. Although the overall number of shots fired calls for service continued to rise after the GDT system was implemented, the increase was smaller in GDT areas, resulting in 22% fewer shots fired calls compared to control areas.

The less exciting news:

• No reduction in violent crime. Fatal shootings, nonfatal shootings, gun assaults, and robberies with a firearm did not decrease in GDT areas compared to the control.

In short: the technology helped police collect more evidence and respond more consistently but it didn’t appear to make neighborhoods safer.

Why Didn’t Gun Violence Go Down?

That’s quite literally a million-dollar question. Kansas City’s system cost between $227,000 and $315,000 per year to operate.

Researchers noted that GDT is covert, meaning it doesn’t act as a visible deterrent. People aren’t necessarily aware that sensors are listening, so any reduction in violence would have to come from behavioral changes such as faster response times, more arrests, or better case clearance.

Collecting more shell casings and evidence is valuable, but it only translates into reduced violence or increased case clearance. Prior studies have shown that pairing GDT with a Crime Gun Intelligence Center to connect recovered casings and firearms to cases and offenders can lead to more case clearances.

So, for agencies without those systems in place, GDT might create more workload than payoff. In Kansas City, officers responded to 8,337 additional gunfire incidents generated by the system, some of which were false positives. Over time, that volume of alerts can reduce enthusiasm and increase burnout.

What This Means for Agencies

If your agency’s goal is to:

• Increase gun recoveries
• Collect more NIBIN evidence
• Reduce the number of unauthorized firearm discharges

Then gunshot detection technology might be worth the investment. It clearly improves police awareness and responsiveness to gunfire that might otherwise go unreported.

But if your agency’s main goal is to:

• Reduce gun violence

Then likely, GDT alone won’t get you there. Agencies need to weigh whether the benefits justify the cost and resources required to operate the system.

Back to Our Agency

As the pilot program continues, the department is taking a close look at what GDT is actually delivering. The sensors have detected hundreds of possible gunfire incidents. Officers are recovering more illegal guns, collecting more ballistic evidence, and arriving at shooting scenes faster than ever before. The technology has clearly improved their awareness of where and when gunfire occurs.

Still, the leadership team is asking the question that motivated the pilot from the start: is this technology helping prevent violence, or primarily just changing how officers respond?

Looking at the evidence from Kansas City offers some perspective. While GDT led to more evidence collection and reduced shots fired calls, it didn’t result in measurable reductions in shootings or other gun crimes. That suggests that while GDT can strengthen evidence collection and potentially investigations, it doesn’t automatically reduce violence.

Now the department faces an important decision: what do they value most? They can continue investing in the sensors to improve evidence collection and reduce calls for service, or they can decide the technology isn’t worth the cost if their priority is reducing gun violence directly. Pairing GDT with other tools or strategies could improve outcomes, but the core question remains whether the investment itself aligns with their priorities.

Final Thoughts

Gunshot detection technology delivers on some of its promises, better evidence collection and more firearm recoveries, but not the one that matters most: reducing gun violence.

That doesn’t make it useless. It just means agencies should be strategic about how they deploy it and realistic about what it can deliver.

As this Kansas City study reminds us: technology can enhance policing, but it can’t replace the systems and strategies that make those enhancements meaningful.

Sometimes, the difference between a worthwhile investment and a wasted one isn’t the technology. It’s deciding what matters most for your department.

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Carlee Ruiz

Carlee Ruiz is the founder of PoliceResearchHub, a platform that turns academic research into practical insights for law enforcement. She brings seven years of experience as a crime analyst and justice researcher, with a focus on evidence based policing, gun violence prevention, and public safety strategy. Carlee currently works as a researcher at National Policing Institute, where she supports evaluations of law enforcement programs and criminal justice initiatives across the country. Through PoliceResearchHub, she aims to make research easier to understand and more useful for the people doing the work on the ground.