DECATUR — Could installing a series of sound sensors on the streets to detect gunfire almost instantly be one way to solve violence in Decatur?
The technology is known as “Acoustic Gunshot Detector Systems” and its deployment on the front lines of American cities plagued with gun violence is increasing.
One of the industry leaders, a California-based firm called “ShotSpotter," now numbers more than 100 police departments among its customers, including Chicago, Springfield and Peoria.
How does it work? A strategically placed series of microphones on light poles or buildings pick up the sound of a gunshot. Using the time the sound takes to arrive at several of those sensors, it's possible to triangulate precisely — like within 50 feet or so — where the sound came from.
If you have any information regarding this homicide, please call Crime Stoppers at (217) 423-TIPS (8477).
That information is flashed to a ShotSpotter command center, where teams of human analysts quickly review to make sure the sound is really gunfire and then send an alert to the local police department. All that happens in less than 60 seconds, ShotSpotter explains, and police patrols are sent a precise map telling them where to go. Faster response times and precise address information means more effective policing and a “greater impact on gun violence," according to ShotSpotter.
That, at least, is the sales pitch. But questions remain about the technology's effectiveness on crime. No one doubts ShotSpotter works, including Decatur police Chief Jim Getz, but he isn't going uniform cap-in-hand to the city council asking for the big bucks he would need to get it. That’s because he’s not convinced ShotSpotter is worth it, and he also isn’t sure the city would be ready for the consequences of what it might reveal.
The issues
No one, including those tasked with protecting and serving, disputes that Decatur is in the grip of a rising gun violence problem. City Councilman David Horn pointed out at a recent council study session with its police chief that, year to date through August, Decatur has seen 102 shootings compared to 48 at the same time last year. Police have made more than 130 arrests for weapons offenses since January 2020. Council members were told by Deputy Chief S. Jason Walker, in charge of the detective division, that his officers were struggling under huge caseloads.
“And it's the same guys getting called in over and over on these shootings,” Walker said. “There is not one detective in my unit that currently does not have multiple shooting investigations and/or homicides…”

In this image provided by ShotSpotter, a screenshot of a computer using the technology is shown. It uses microphones to detect gunshots.
Getz, Walker’s boss, put it more bluntly. While praising the heroic efforts of his officers and their above average clearance rates, the chief said the strain of the workload was crushing: “Our guys are getting burned out and you can only work them so hard before they become a risk to themselves or to the public,” he told council members.
So why not make life easier by investing in ShotSpotter? Getz said cost was the first headache. While the city is grappling with a budget shot full of holes by the economic malaise induced by COVID-19, Getz did his own research and priced the deployment of ShotSpotter in Decatur at $280,000 to start, followed by annual $250,000 fees for the leased and licensed gear and support services.
Those numbers, he said, are based on a coverage area of 3 square miles based in turn on a “heat map” police composed of where most shootings go down.
Getz said chatting about it with other police chiefs showed him ShotSpotter was a good “investigative tool," but it won’t transform your arrest numbers.
That view is borne out by a study published in Police Chief Magazine that looked at results from Acoustic Gunshot Detector Systems deployment in St. Louis, which currently uses ShotSpotter. After crunching data over 10 years involving some 19,000 calls prompted by the detectors, the study found police were led to the scenes of five homicides, 58 aggravated assaults and two robberies.

Wearing a body camera, Officer Sean Bowsher stands in front of the Decatur Police Department.
After cross-referencing calls with arrest data, the study could identify only 13 arrests uniquely associated with AGDS calls. “For a city with between 100 and 200 homicides annually, that is not exactly a great catch …” the magazine concluded.
But Getz said the evidence does firmly establish that those unsleeping electronic ears will hear more gunshots than anybody realized, which may present a whole new set of problems, whatever the actual arrest results. He said talking to other departments using the technology revealed that shots fired alerts jumped an incredible 80 percent, meaning that police, relying on their own ears or 911 calls, were only hearing roughly 20 percent of the actual gunfire taking place before ShotSpotter arrived.
Getz said being confronted with that reality and its consequences is something the city council might want to consider carefully before it pulls the trigger on cracking open Pandora’s acoustic box.
“And so with ShotSpotter, you are going to have an accurate count of our shootings, of people out there shooting, and you may not want to know that number; that is for you guys to decide,” said the chief, addressing the council at the recent study session. “And then the other portion of that is your calls for service are going to go up… and so you had better have enough officers to staff it.”
Councilman Horn, who has been for several ride-alongs with patrol officers, seemed astonished at the potential shooting numbers and, extrapolating from the current known shooting stats, estimated that Decatur actually had “about two a day” of shots-fired incidents.
Knowledge is power
ShotSpotter maintains that knowing that reality in real time is the first step in being able to deal with it. That was the view outlined by Sam Klepper, senior vice president of marketing and product Strategy for ShotSpotter.
He told the Herald & Review: “If police use ShotSpotter and follow best practices… respond to an alert ShotSpotter gives, go to the scene quickly, get out of the car and look for shell casings which, when found, can link a gun to multiple crimes and ultimately identify a suspect, if they follow these basic steps we find cities are very successful in reducing gun violence over time.”
He cites Las Vegas as an example of the dampening effect the use of ShotSpotter can have on gun crime. He said Las Vegas saw a 26% reduction in violent crime in one year with no other changes being implemented than the use of ShotSpotter.
And it isn’t just the company singing its own praises. Former Chicago Police Superintendent Kenneth Johnson credited the use of the ShotSpotter technology, along with other tools enabling cops to work “smarter and faster," with homicides and shootings dropping by 40 percent in the city’s Englewood patrol district in 2017.
There also have been privacy concerns, as the sensors constantly record audio. In Detroit, plans to use the technology this summer faced opposition after parallels were drawn to the controversial use of facial recognition systems and surveillance cameras during protests following the death of George Floyd in Minneapolis. The U.S. Department of Justice this summer directed about $1 million in crime-fighting resources to Detroit, with about $100,000 for gunshot detection systems.
Company officials over the years have pointed to various policies in place for how the audio is stored and used.
The Peoria Police Department is another believer in the soundness of the technology, which it first deployed in 2013 and has been happy to pay for recurring contracts with the firm which can run more than $450,000 over three years.
Public Information Officer Amy Dotson said Peoria police don’t want to hit the streets without their electronic gunshot ears: “For our city, it’s been wonderful,” she added. “And it’s been a great investigatory tool.”

Macon County Sheriff's Department Sgt. Lisa Friis views the monitors in the surveillance room at the Macon County Courthouse in Decatur.
She ticked off the benefits: getting a precise gunshot location instead of relying on members of the public calling in, often with only a vague idea of where any shots came from, and how many there were.
“With calls like that, you are basically searching for a needle in a haystack,” she explained. “Now fast forward to ShotSpotter, and within 60 seconds of that gunfire being detected the information is sent to Peoria police dispatchers and to the appropriate squad cars in that area. In perfect conditions, it can even tell you whether it came from a front yard or a backyard.”
And regardless of the outcome of an investigation, Dotson said a bigger priority was trying to save victims from dying. “I would argue the most important aspect is getting to the victim quicker and rendering the aid that they need to save their lives,” she added. “ShotSpotter is a win in our book.”
Under surveillance
So with the jury still out on whether Decatur will ever see and hear ShotSpotter, there is some older electronic policing technology that is on the way: street surveillance cameras.
Deputy City Manager Jon Kindseth said that, with the help of the Howard G. Buffett Foundation, state-of-the art cameras will be part of the massive new redevelopment of the city’s Johns Hill neighborhood. And it’s likely to prove the advance guard of surveillance camera deployment to keep an eye on potential trouble spots all over the city.
“We’re going to use the Johns Hill neighborhood as a pilot project for a larger area, to be deployed where necessary,” Kindseth said. “With Johns Hill, the cameras will be probably be deployed later this year or next year.”
Watch now: Decatur police chief discusses camera usage to solve crimes
Decatur’s police chief can’t wait to see them dotted in sensitive crime areas where law enforcement needs eyes around the clock. The department already has eight cameras installed in certain neighborhoods to address crime and officers this fall were equipped with body cameras.
“If you ask me, professionally, would I choose street surveillance cameras or ShotSpotter? I would take the street surveillance cameras any day. Any day,” Getz told the city council.
Getz said the cost was much cheaper, and you pay a one-off fee for the hardware up front. “You will solve more cases and stop more crime with the street surveillance cameras than you will with the ShotSpotter, based on conversations I’ve had with other (police) chiefs,” he added.
Macon County Sheriff Tony Brown agrees on that point, too, and says his department has deployable cameras they can set up in rural areas being plagued by issues like house or workshop burglaries. “It gives us eyes on an area, and it's effective,” he added.

Macon County Sheriff Tony Brown
City council members tasked with paying for it with taxpayers’ money also appear sympathetic to using electronic eyes rather than ears to detect crime. “Yeah, I think cameras would help,” said city councilman Rodney Walker.
And he isn’t too worried about privacy concerns as the city battles an epidemic of gun violence. “It’s just like with speeding on the highway,” he explained. “The only people concerned about the speed limit are people who speed, and the only people concerned about cameras on the public streets are people who commit crime.”
How ShotSpotter works
1) Firearm is fired

A gun is fired and the sound of the muzzle blast radiates outward from the barrel.
2) Gunshot is detected and located

ShotSpotter technology uses acoustic sensors posted in different locations to determine that firearm was fired. By triangulating information from multiple sensors, a precise location is determined.
3) Gunshot is reviewed

The data is reviewed and police are notified.
4) Police respond

Alerts are sent to dispatch centers and officers.
Contact Tony Reid at (217) 421-7977. Follow him on Twitter: @TonyJReid