How ShotSpotter and New Technologies Help Police Fight Crime

BIG BANG THEORY: A high-tech system that tracks where a gunshot is fired appears to be an effective weapon in the fight against crime
Illustration by Michael Byers

On a balmy June afternoon, Elizabeth Taybron paused while walking home to chat with neighbors in her southeast Saginaw neighborhood.

After their friendly exchange, the 70-year-old, known to many in the neighborhood as Ms. Elizabeth, resumed her slow gait. But Taybron, who lived just around the corner, didn’t make it far before suddenly collapsing. Within minutes, two police officers responded to a 9-1-1 call reporting the incident. They found her unconscious but breathing, lying in a pool of blood. She’d been shot in the back of the head — an injury that left her mostly comatose until her death six months later.

“She [was] so far away that the people she was talking to didn’t even hear the gunshot,” Saginaw Police Chief Gerald H. Cliff says.

A number of witnesses told police they heard nothing unusual until the wail of sirens disturbed that summer day. Others reported hearing gunshots or loud bangs.

While the human accounts painted an unclear picture, another kind of witness told a less ambiguous story. ShotSpotter, a firearm-detecting system that pinpoints the location of a gunshot, had been operating in a square-mile area that includes the corner where Taybron was struck, as well as the spot nearly three football fields away — more than 800 feet — where a single gunshot had registered at almost exactly the same time she reportedly went down.


The ShotSpotter system, implemented in Saginaw in early 2009, is composed of a series of acoustic sensors mounted on telephone poles, building rooftops, and other inconspicuous locations in a predetermined area. The pizza-box-sized sensors employ GPS technology to triangulate a gunshot’s location, using a formula based on the speed of sound to calculate the exact location from which a noise above a certain decibel level emanates. The time between when a gun is fired in a ShotSpotter zone and when police receive detailed information about its location on their in-car laptops is measured in seconds — a span that could mean the difference between life and death.

There have been skeptics of ShotSpotter’s merits, but in a city where rampant gun violence has terrorized residents, business as usual was not an option for police. When Cliff stepped in as Saginaw’s chief in 2005, he says he found “a city that was more interested in cutting the grass on the boulevards than keeping police on the street.” From 1999 until 2006, the city eased its budget deficit by reducing police-department personnel, Cliff says. Mid-career officers were worried about being laid off. Morale was low, which was reflected in the numbers. While violent crime nationally was falling, Saginaw saw a spike that culminated in 2008, when the city recorded more than 150 shootings — no small number given the population of roughly 55,000. The national media cited Camden, N.J., St. Louis, and Detroit as murder capitals, but turmoil within the namesake city of the Saginaw Bay went underreported, thanks to its small size. “When I was offered the job up here, I had no idea how bad it was,” Cliff says.

When he changed the parameters to cities with more than 40,000 residents, the result was shocking. “The unbelievable amount of shooting and homicide that we had in this city per capita put us in front of Camden, N.J. It put us more violent than Detroit,” Cliff says. “We are No. 1 in the nation from 2003 until 2009.”

When folk duo Simon and Garfunkel sang about hitchhiking from Saginaw in the 1972 single, “America,” they weren’t the only ones leaving the city. “We suffer from the same maladies that every other industrialized Rust Belt city in this part of the country suffers from,” Cliff says, speaking from behind his desk in the second-floor office of a building that was a Sears department store when the city had double its current population. As a 31-year veteran of the Detroit Police Department and a longtime Detroit resident, Cliff has seen firsthand how his adopted city has mirrored his hometown. “We used to house eight General Motors facilities here that employed almost 40,000 people,” Cliff says. “We now have one left with just a little over 800 employees.”

The Saginaw Police Department is in one of a few occupied buildings in the city’s downtown. Many businesses have fled to Old Town, an area in the early stages of gentrification on the other side of the Saginaw River. In the context of modern-day Saginaw, the Paul Simon-penned song about finding meaning in America takes on a bleaker tone than he might have intended. A street artist has emblazoned the lyrics in the form of graffiti across dozens of abandoned structures. Graffiti on a particularly decrepit building near Cliff’s office sums it up: “All gone to look for America.”


This picture ignores the positives, though. As Cliff tells it, the foundation of a slow turnaround was established in 2006 — two years before crime peaked — when the city manager asked the community for a vote of confidence in the form of a five-year millage to maintain public-safety staffing. Meanwhile, the police department began fostering a community-policing program, and new neighborhood associations were springing up. “It was like a relationship-building process through the whole thing, and it began to pay off toward the end of the five-year millage, which is right now,” Cliff says.

In 2009, ShotSpotter’s first year in action, the city hit an eight-year low in violent crime. The following year, after installing an additional square-mile ShotSpotter zone on the city’s west side, Saginaw saw its safest year in three decades. The apparent success of the new technology could be interpreted in one of two ways: It came just as other efforts were beginning to grow fruit — or it just works.

One key aspect to its success has been not publicizing the exact coordinates of the city’s two ShotSpotter zones. “I’ve got 17 and a half square miles of effect for two square miles of investment, simply because we kept its location under wraps,” Cliff says.

This result is not uncommon. When the technology was first implemented in Redwood City, Calif., in 1996, it was so clumsy that a slamming Dumpster lid would trigger the sensors. According to a profile of ShotSpotter in Wired magazine, it could locate gunshots only 45 percent of the time in tests. But, remarkably, it still proved quite effective, thanks to good publicity. “Authorities bragged to reporters that if anyone fired a gun within city limits, the police would be there in moments,” Wired’s story noted. The technology has greatly improved since then, but Cliff says word-of-mouth generates a value-added effect. “We publicize the living daylights out of it,” he says.

And while ShotSpotter led to a key piece of evidence in Taybron’s shooting (at press time, the case against the alleged shooter was set to go to trial June 21), its biggest achievement has been deterrence, Cliff says. “We’ve only had four or five major incidents where we’ve gone to court with ShotSpotter. But what if ShotSpotter didn’t exist?” Cliff says. “We’d still be the most violent city per capita for a 10th year in a row — and an 11th.”

But measuring ShotSpotter’s benefits has proved challenging. “It wouldn’t have been ethical for me to say, ‘We’ve got the most violent city over 40,000 in the nation. Let’s try one thing and hold everything else constant and see how many people are dead at the end of the year.’ I had to use every single tool at my disposal,” Cliff says. “I had to come up with every possible strategy that we could think of to try to turn back the rising tide of violent crime in this city. We threw everything at it that we could think of that we could make work. Technology — is that a big part? It’s a huge part.”

But it’s not the only part, and that’s a point that Detroit Police Chief Ralph Godbee Jr. often emphasizes when discussing technology’s effect on policing. “When you exhaust every technological resource, you need a body to go out and lock [someone] up,” Godbee says. “Sometimes there can be an over-reliance on technology to the extent where we can forget the good old-fashioned police work: You get out there, you pound the pavement, you talk to people, you build relationships, and build rapport with the community. Technology can’t do that.”


In Detroit, homicides and nonfatal shootings were up in the first quarter of 2011, prompting calls for increased prevention. That makes plans for Detroit’s own upcoming ShotSpotter pilot program (covering two five-square-mile zones) especially welcome news. As in Saginaw, the two zones will be located where violent crime has been most prevalent.

Detroit’s size might prove challenging. The entire city of Saginaw is an area about the same size as a single Detroit police precinct. Deputy Chief André Simenauer, who heads Detroit’s Technical Services Bureau, isn’t concerned. “You’d be surprised,” he says. “We actually initially started out with 5 square miles. We started looking at it and said, ‘You know what? To do this right, we’re going to have to break it up into two non-disclosed 5 square miles.’ ”

“Much to probably most people’s surprise, the entire city of Detroit is not a hot spot,” Godbee says. “There are areas that we definitively know that — based on the data — we need to apply a certain set of resources. … All 140 square miles don’t have the same issues.”

The other factor affected by Detroit’s size is cost. U.S. Rep. Dale Kildee secured funding for Saginaw’s ShotSpotter program through federal earmarks. The first square mile of the program cost Saginaw more than $280,000. But the City of Saginaw also has its books in order, and isn’t teetering on the brink of receivership, as Detroit is. Based on the cost of ShotSpotter in Saginaw, the Detroit pilot could approach a $3-million price tag. Where will that money come from? Godbee says the pilot will be paid for by federal-forfeiture funds and a justice-assistance grant from the U.S. Justice Department.

“[ShotSpotter] has some [Department of Defense] certifications from a Homeland Security standpoint, to where the technology is recognized by the federal government, and it’s going to be a significant infrastructure in Washington, D.C.,” Godbee says. “We felt that if we take this initial investment and hone our utilization of it, it’s our plan to expand it beyond those 10 square miles as we understand the technology better.”

But getting Detroit’s initial 10 square miles up and running is a process in itself. Because of the level of funding requested, the plan requires City Council approval, Godbee says. He and Simenauer remain optimistic that it will be installed this summer and operational by fall. “It’s a tremendous tool from the standpoint that it gives our officers an ability to go — in fairly real time — directly to where a shot is coming from,” Godbee says.


This will be a busy summer for Cliff and his team in Saginaw, too. While some residents will enjoy lazy days at the city’s new splash park, important work will be occurring in a plain building that appears to be the park’s janitorial headquarters. Inside, however, is the home base of Saginaw’s community-policing program, and phase three of its technology effort, dubbed RAPTOR (Regional Analysis of Police Technology and Operations Reporting). According to Cathy Starling, Saginaw Police technical services supervisor, 35 wireless cameras — funded by another Kildee-secured federal grant — will be paired with ShotSpotter. The RAPTOR Control Center will receive camera feeds, as well as feeds from other private-security firms. When ShotSpotter gets a hit, a surveillance camera in the area will send high-definition video from the location, giving officers a real-time visual of the scene. Cliff says the cameras can read a license plate from 400 feet away.

ShotSpotter sensors are triggered only by gunfire. (Other loud noises such as fireworks or a car backfiring will also set them off, but these are then reclassified by officers. Over time, the system learns to differentiate them from gunfire). “The sensors will not, at all, pick up a conversation,” Starling says. “It’s only picking up the bang.” But the third phase of Saginaw’s program, the surveillance cameras, have added a civil-rights concern.

“This is why it gets awfully tricky,” says Kary L. Moss, executive director of the American Civil Liberties Union of Michigan. “There could be any number of ways that cameras can be used effectively. The question is: Have we thought it through to manage it for potential abuses for overreaching and effectiveness?

“It could be that [it] will be fine — inoffensive, effective. But how else might those cameras be used? And are there any boundaries around it at all?”

Cliff and Starling say they’ve received no resident complaints. “It doesn’t look into windows,” Cliff says, so there isn’t much to worry about.

But that doesn’t mean there isn’t a degree of concern. “A surveillance camera that may have gone up 10 or 20 years ago that was in a fixed place and could see things from a distance may now be able to see what somebody sitting on a park bench is reading,” Moss says.

And the effectiveness of surveillance cameras, Moss says, hasn’t been proved. “The positive expectations that we have of cameras improving crime are shown to not be true,” she says; they simply move the crime to areas where the cameras can’t see. “Research is showing that [cameras] create a false sense of security. People think that they’re safe, but they’re not — putting them in more danger.

“Research has also shown that cameras have minimal investigative value. In Lansing, the police say they’ve been able to identify littering or public urination [with surveillance cameras], but they have not solved many violent crimes.”


But RAPTOR is different, Cliff says, because of ShotSpotter augmenting the data. Even The Saginaw News has chimed in with an editorial headlined: “Civil liberties worries aside, Saginaw’s RAPTOR system a good idea.”

“With Saginaw earning national recognition for the violence that has occurred within the city limits, local police would be foolish not to use every tool at their disposal to keep residents safe,” the editorial reads. “This has the potential to do that.”

Detroit, too, is taking a novel approach to its various tech efforts. The police department publishes most of its Part-One crimes (the most serious crimes) on, which then charts each incident on a city map. The department also has implemented a tip line that allows cell-phone users to anonymously report crime via text. On the reverse end, a Citizen Observer program emails and texts information such as descriptions of wanted suspects, missing persons, crime-prevention tips, and other public-safety information back into the community. “We’ve made a huge commitment to transparency and community policing,” Godbee says. “For us to ask the community to participate with us in reducing crime, that’s the tools we have to provide to them.”

“Technology is a big part, but it’s not the only solution,” Cliff says, when asked about applying his strategy to Detroit. “You’ve got to have your citizens engaged in working with the police department. That’s tough in a big city. There isn’t the personal aspect that we have in a smaller town.”

For both cities, what it really comes down to is a mantra so many are familiar with these days: Do more with less. Saginaw’s police force is less than two-thirds the size it was in 1999; Detroit has lost 1,200 officers in six years. Cliff says one of the criticisms he got when implementing ShotSpotter was from union representatives seeking to have that money allocated toward personnel. Cliff says that $500,000 “would have paid for one police officer for five years, with less effect.”

Cliff, a self-described tech-head, says that his department in Saginaw has benefited from employing a relatively young force for whom new technology is second nature. But even if the technology can’t take all the credit for driving down crime, Saginaw is doing something right. “This was the bane of central Michigan’s existence for a while — Saginaw,” he says. “Now, all of a sudden we hit a 30-year low in the violent-crime index … everybody in Genesee County is going, ‘We’ve got to learn from Saginaw. What’s Saginaw doing? Because whatever they’re doing, they’re doing it right.”

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