Updated on April 30, 2024: Some major cities are considering whether to abandon the controversial gunfire detection system ShotSpotter, as a chorus of critics accuses it of inaccuracies, racial bias and lack of transparency. But in Pittsburgh, city officials are expanding the technology’s use.
Pittsburgh City Council voted unanimously Tuesday to approve a $133,000 expansion of the city’s contract with SoundThinking, the company behind ShotSpotter, to include the Carrick neighborhood.
But discussion about the future of the artificially intelligent listening devices in Pittsburgh appears to be far from over. Multiple council members called Tuesday for a broader public discussion about ShotSpotter's use in Pittsburgh.
"I think a robust discussion is in front of us," said Councilor Deb Gross.
Councilor Barbara Warwick, who'd been critical of ShotSpotter in a council discussion last week, was absent from Tuesday's meeting. But echoing sentiments raised in that discussion, Councilor Khari Mosley said the city should seek input from residents about their experience with ShotSpotter.
"When we come to the decision of deciding to either renew the contract or not, I think that the public deserves to be a part of that robust conversation," he said.
Pittsburgh’s Bureau of Police uses ShotSpotter sensors in all six police zones. The exact locations have not been disclosed, but company documents previously obtained by WIRED suggest they have been positioned throughout the North Side as well as the Hill District, Garfield, Larimer, Homewood and other eastern neighborhoods. Cameras are also clustered in the South Side Flats, South Side Slopes and Allentown.
Police Chief Larry Scirotto claims ShotSpotter saves officers time when responding to gunshots, which can be the difference between life and death for a victim.
“ShotSpotter technology gives us a much more defined location ... our officers are responding to the victim where they're most likely at,” Scirotto told council last week. “Without this technology, they cannot do that.”
He said that if it weren't for the system, officers would have to rely on 911 calls, which can furnish much less information than ShotSpotter’s microphones provide.
And as Pittsburgh continues to grapple with a shrinking police force, Scirotto says technology like ShotSpotter can help keep the city safe with fewer officers. Last month, the bureau announced it would respond to fewer calls for nonviolent crimes, instead referring people to the telephone reporting unit or filing a report online in an attempt to free up officers to respond to violent crimes.
Scirotto told council last week that nearly 80% of homicides in the city between 2022 and 2023 took place within range of ShotSpotter equipment.
But critics argue that a lack of transparency about the system should be reason enough for officials to ask more questions before making use of it.
Among the questions council members discussed last week: How reliable is ShotSpotter at detecting actual gunshots?
Firing blanks?
The city pays roughly $1.2 million per year for Shotspotter, which uses a network of microphones to detect potential gunshot sounds. SoundThinking’s algorithm classifies potential gunshot sounds that are then confirmed or rejected by the company’s employees.
Pittsburgh Police officials have told council that a “scorecard” they received from SoundThinking claimed that the Shotspotter devices in Pittsburgh were only wrong between 4% and 8% of the time.
But according to Kade Crockford, director of the Technology for Liberty program at the American Civil Liberties Union of Massachusetts, the technology was found to be deeply flawed in Boston. The ACLU reviewed 1,300 reports detailing the Boston Police Department’s use of ShotSpotter between 2020 and 2022, and found that in nearly 70% of ShotSpotter alerts, police found no evidence that gunfire had taken place. In 16% of cases, officers found that the technology had wrongfully identified other noises — including construction sounds, cars backfiring or fireworks — as gunshots.
“That indicated for us that the technology is not really doing very well,” Crockford said. “And it raises a number of concerns.”
In an interview with Boston radio station WGBH earlier this month, a SoundThinking executive claimed that an internal review of millions of incidents across 170 cities found that ShotSpotter accurately detected the sound of gunfire 97% of the time.
“Just because police don’t locate the evidence of a shooting doesn’t mean the shooting did not occur,” Tom Chittum, SoundThinking senior vice president of forensic services, told the station. He did not disclose how the technology's accuracy was determined.
Crockford argued it’s hard to verify those figures for Pittsburgh without independent evidence. “ShotSpotter has never opened up its technology to independent assessment," they said.
The danger, Crockford added, isn't just that police waste their time. False ShotSpotter notifications could send police “rushing into neighborhoods of color looking for shooters who may not exist,” they warned — potentially exacerbating “an already strained relationship between police and communities of color.”
Criticism of Chicago’s use of ShotSpotter was widely reported as the city weighed whether to end its contract with SoundThinking earlier this year. The debate stemmed from a January incident where the gunshot detector erroneously alerted police to a shooting. Officers arrived on the scene where one officer fired a gun at an unarmed child.
In another case, a Chicago man was jailed for nearly a year on charges supported solely by ShotSpotter evidence. A judge later dismissed the case against him citing insufficient evidence.
Some on City Council flagged those incidents in their discussion last week.
“A number of cities across the United States are quite clearly saying this tool doesn't live up to what it has promised to do,” said Warwick.
But Scirotto argued that Pittsburgh has different policies than Chicago.
Chicago authorities "used information inappropriately to further support their case,” Scirotto said. “We don't use it as a matter of probable cause” to justify charges, he said. “We use it as a matter of safety and information.”
'At least it'll give police another tool'
According to public safety officials, ShotSpotter currently covers 18 of the city’s roughly 56 square miles. But the city isn’t aware of exactly where all the company’s microphones are located.
“The only sensors that we know [of] are the ones that are on city facilities,” said Daniel Shak, director of the city’s office of public safety technology. He said the city shares crime location data with SoundThinking but the company makes its own agreements with property owners about where to locate their devices.
Secrecy surrounding where these 24/7 listening devices are located has been criticized by civil rights advocates who argue SoundThinking and local governments should be more transparent.
Warwick and some others on council suggested the city controller's office conduct an audit of the system's use, including the location and accuracy of the microphones.
“It’s very unclear to me why we don't have all of this information already,” Warwick said.
But it’s not certain that such an audit could be made public, given the terms of the city’s contract with SoundThinking. And Crockford argued that cities should look at what information is already available as a reason to investigate the technology further.
“Communities that are concerned about things like gun violence ought to be reflecting on whether or not continued investment in a technology that produces such poor results statistically is a sound investment,” Crockford said.
Critics also argue that the technology is often stationed in predominantly Black neighborhoods, which could exacerbate racially biased policing.
Information about exactly where the devices are installed had not been released to the public until the WIRED report. It produced a nationwide map of the nearly 26,000 ShotSpotter microphones — many of which found to be on top of schools and hospitals as well as within public housing complexes.
Scirotto argued ShotSpotter’s locations were determined based on crime data.
“[The technology] wasn't taking us to a neighborhood that we wouldn't otherwise have been in,” he said. “The gun crime was taking us to that neighborhood.”
City Council President Dan Lavelle said several Black neighborhoods initially “requested this technology to come into their community.”
Lavelle said he strongly supported the use of ShotSpotter.
While the system costs the city $1.2 million per year, he said, “I would actually say I'd be willing to spend even more than that to save those lives. But at a minimum, that is worth it to me.”
Some in Carrick would like to see a similar investment in their neighborhood, which has seen seven shootings between 2023 and this month. Four of those shootings were fatal. Carrick Community Council member Gordy Sullivan has been hoping the technology would make its way into his neighborhood for years.
“At least it'll give police another tool in the Carrick neighborhood to help probably solve some crimes,” he said. “We’re trying to do a lot of good in Carrick and just get the neighborhood built back up and try to keep it peaceful.”
'We have a test case'
The technology’s expansion into Carrick won't affect the length of the city’s contract with SoundThinking, which ends next year. But council's debate appears likely to set the stage for an expansive discussion about the system's long-term future.
Half a dozen people spoke against the use of ShotSpotter during the public-comment portion of council’s committee meeting last week. Several identified themselves as software engineers and data scientists and pointed to recent research that shows ShotSpotter has not been proven effective at decreasing homicide rates.
Seven of the city’s nine council members preliminarily voted in favor of expanding the technology to Carrick: Warwick and Theresa Kail Smith abstained from voting last week. Kail Smith said her final approval was contingent on further private discussions with the police chief.
Warwick, who worked in IT prior to winning a seat on City Council, largely spoke against the technology. She said the city should hold public hearings on gunshot detection software to better educate the public and city leaders on its use.
Warwick advocated for the city to collect extensive data on violent crime in Carrick now and after the installation of ShotSpotter devices. “We will literally have an apples-to-apples [comparison,” she said. “We have a test case right here.”
Public Safety director Lee Schmidt said the city plans to watch Carrick closely to see how the technology impacts policing and public safety in the neighborhood.
“That is something we're hoping Carrick will be a good example of when it wasn't there versus when it is there,” he said.
