Incident 112: Accuracy of ShotSpotter Gunshot-Detecting Algorithms Cited as Unreliable

Description: ShotSpotter's precision in locating gunshots via algorithms was revealed to be unreliable and fabricated in a court case in which the algorithm failed to pinpoint accurate location of a crime.
Alleged: ShotSpotter developed an AI system deployed by San Francisco Police Department, which harmed San Francisco public.

Suggested citation format

Perkins, Kate. (2016-04-01) Incident Number 112. in McGregor, S. (ed.) Artificial Intelligence Incident Database. Responsible AI Collaborative.

Incident Stats

Incident ID
112
Report Count
9
Incident Date
2016-04-01
Editors
Sean McGregor, Khoa Lam

Tools

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Incident Reports

TROY — The cops on the beat, the brass and the mayor all agree that the high-tech listening system that's supposed to identify the location of gunshots is ineffective.

That's why the city has decided to get rid of the ShotSpotter system at the end of the year.

"We are discontinuing Shot-Spotter," Chief John Tedesco said Tuesday night during the Public Safety Committee's review of the police department budget for 2013.

Dropping the system means the city will save $39,000 in annual costs. Tedesco said the company had been pressuring the department to upgrade the system, which would have moved monitoring to California instead of in police headquarters.

The displeasure with the acoustic surveillance system is so prevalent that Tedesco and Officer Robert Fitzgerald, the Troy Police Benevolent Association president, who usually disagree on issues, both agree that it's time is over.

"We're getting a better response from the public," Fitzgerald said about calls residents made to report gunfire.

The chief and union president said the patrol officers supported dumping ShotSpotter.

Tedesco said the system never achieved what it was suppose to do when the city installed it for $250,000 in 2009 using drug forfeiture money to cover the cost.

"It wasn't reliable," Tedesco said.

It also was expensive, the chief said. Moving one of the listening devices, he said, cost $6,500.

The system was suppose to become attuned to the way sounds were heard in Troy's streets and differentiate among the brakes of a truck climbing the Hoosic Street hill, from a firecracker, actual shots and any other noise.

Tedesco said this was never completely achieved.

Mayor Lou Rosamilia said he backed the decision to end participation in ShotSpotter.

"It's not working in the way it's suppose to," Rosamilia said.

A ShotSpotter spokeswoman could not be immediately reached Tuesday night for comment.

Troy installed a network of 22 acoustic listening devices to cover the neighborhoods with the highest crime incidents.

The city rolled out the surveillance devices with great fanfare in late 2008. It was supposed to lead officers to the sites where shots were fired when not reported by the public.

Rosamilia, Tedesco and Fitzgerald each said that unlike in some cities, Troy residents call in reports of gunshots.

At first, police touted the system as an early success. Each patrol car had access to the computerized monitoring system installed to allow officers to get the information firsthand.

It was expected to take a full year to fine-tune the acoustic devices so it would pick out the gunshots from other sounds. Tedesco said that never occurred.

The listening devices were placed to cover an area that ran from Lansingburgh south through downtown and into South Troy. The system also picked up sounds from the Rensselaer Polytechnic Institute campus.

Retired Chief Nicholas Kaiser pushed for the installation of the system, which was supported by former Mayor Harry Tutunjian.

Troy will turn off ShotSpotter

The accuracy of gunshot detection technology used by San Francisco police has been called into question as part of an attempted murder trial of a man accused of shooting at a car full of people in 2016.

While the trial of Michael Reed in connection with a shooting on Aug. 13, 2016 specifically focuses on ShotSpotter sensors in the Western Addition, it raises questions about issues with gunshot detection sensors elsewhere in The City.

Since 2008, the gunshot detection technology has recorded all loud noises and reported the ones thought to be gunshots to San Francisco police, so they can quickly respond.

Paul Greene, a forensic analyst with ShotSpotter and an expert witness in Reed’s trial, testified on Thursday in San Francisco Superior Court about the technology’s accuracy. Manufactured by the company SST in Newark, Calif., ShotSpotter guarantees accuracy 80 percent of the time.

In Reed’s case, ShotSpotter failed to pinpoint the exact location of Reed’s alleged crime near Turk and Buchanan streets, according to Greene’s testimony. In fact, additional analysis conducted after the shooting, at the behest of police, determined the location was about a block away from where it was first reported.

“The computer was wrong?” asked Deputy Public Defender Michelle Tong, who is representing Reed.

“Yes,” Greene replied.

In a broader sense, Greene said the gunshot detection system used by the San Francisco Police Department has not been recalibrated in almost a decade and that ShotSpotter’s guarantee of accuracy was invented by the company’s sales and marketing team.

“Our guarantee was put together by our sales and marketing department, not our engineers,” Greene said.

“We need to give them [customers] a number,” Greene continued. “We have to tell them something. … It’s not perfect. The dot on the map is simply a starting point.”

The accuracy of the system is significant in Reed’s case because police found nine shell casings at the scene, while ShotSpotter recorded 11 shots.

Tong contended that Reed fired in self-defense at someone who first fired at him, hence the extra shots.

However, prosecutor Christopher Ulrich said video and the ShotSpotter recordings showed Reed firing most of the gunshots, while the extra shots were fired by a co-defendant, not an enemy.

Despite the testimony, SST’s CEO Ralph Clark said the technology is better than the guarantee, and SFPD officials were positive about the technology.

The public typically under report gunshots and have little idea where they come from, according to police.

“This technology pinpoints where [gunfire] is,” Deputy Chief Mikail Ali said. “If you’re only relying upon the public, we are significantly under reporting.”

Police spokesperson Robert Rueca said officers respond to all ShotSpotter calls. Still, Rueca would not say how many gunshots are reported each year or if the department verifies their location accuracy.

“It points in the direction to where we might want to go and investigate,” Rueca said.

ShotSpotter, which the manufacturer claims helps reduce gun violence, can pinpoint “precise locations for first responders aiding victims, searching for evidence and interviewing witnesses,” according to SST’s website, which also noted the technology can report the number of shooters and shots fired.

The company’s technology is used by about 90 law enforcement agencies across the country, but some departments have decided to axe the service in recent years.

In 2016, the Charlotte-Mecklenburg Police Department in North Carolina did not renew its annual contract with ShotSpotter because it failed to help them make arrests or identify victims.

In 2012, the Detroit Police Department canceled its ShotSpotter contract because the city had other priorities and not enough officers to respond to reported gunfire.

And in 2014, the Oakland Police Department considered ending their contract for the same reason, but they still use it today.

ShotSpotter was placed in three San Francisco neighborhoods with high crime rates — Western Addition, Bayview and Mission — in 2008.

In 2010, a grant from the U.S. Department of Justice for $1 million paid to expand use of the gunshot technology from 3.3 square miles to 4 square miles, and included new neighborhoods such as Visitacion Valley. It expanded again in 2014 in the Bayview, Western Addition and Mission.

Since fiscal year 2012-13, The City has spent $1.6 million on the ShotSpotter annual contract.

Neither SST nor police would divulge how many sensors are in San Francisco, but Clark said there are about 25 per square mile in the outfitted neighborhoods. For example, during a two-month period in 2009, ShotSpotter recorded 244 gunshots across The City. In 2010, the technology recorded 177 in the same two months.

The system records all loud noises, Greene said. The computer uses at least three microphones to locate the gunshot within a 25-meter radius. Then, at SST’s location in Newark, staff reviews each report to make sure the computer flags only gunshots.

The two-decade-old company went public June 7 and raised $30 million in NASDAQ share purchases and had previously raised $67.9 million from 12 venture capitalists.

But the technology’s accuracy depends on everything from topography, temperature, humidity and wind speed, as well as the trained ears of employees, according to Greene.

Clark acknowledged the accuracy of the technology is not perfect, nor is their guarantee, but he did say it works.

“The 80 percent is basically our subscription warranty, as you will. That doesn’t really indicate what someone will experience,” he said, adding that it is usually far better.

Despite changes in topography in the Western Addition, from new buildings to taller trees, the 46 sensors there have not been retested since they were first put in, Greene testified last week.

But Clark said the company uses other tools to perfect its system, like customers who notify them of gunshots that were not reported, which they call “missed gunshots.” They also keep track of possibly faulty sensors.

Finally, there are false positives, in which there is a gunshot reported with no evidence of any gunshot.

“We do have a team that analyzes this on a regular basis,” Clark said.

Courtroom testimony reveals accuracy of SF gunshot sensors a ‘marketing’ ploy

In his campaign to win re-election and convince voters he was tough on crime, Councilman Alan Warrick never missed a chance to bring up ShotSpotter, a pricey gunfire detection system he championed for his East Side district.

Of the 10 council districts in San Antonio, Warrick’s had racked up the most homicides in 2016. The councilman argued ShotSpotter was the key to helping quell the problem, ensuring police responded to gunfire even if residents were too scared to call 911.

But after only one year in operation, and less than three months since Warrick lost his re-election bid, the city has recommended cutting ShotSpotter funding entirely. The item is not included in the proposed FY 2018 budget.

The reason: it simply wasn’t worth the cost, city officials say.

In the 15 months it’s been in operation, officers have made only four arrests and confiscated seven weapons that can be attributed to ShotSpotter technology, Police Chief William McManus said.

The technology itself cost about $378,000. But the city spent another $168,000 on officer overtime for the program, the chief said.

That’s $136,500 per arrest.

The four suspects were arrested on charges of discharging a firearm, a Class A misdemeanor, the SAPD’s Sgt. Jesse Salame said. One of the suspects also was charged with possession of narcotics.

There was no known shooting victim in any of those four cases, Salame said.

At a budget session Wednesday, McManus told council members there has been no reduction in gunfire in the areas where ShotSpotter was used.

“We made a better-than-good-faith effort trying to make it work, trying to produce the results we wanted to see, results that spelled success for us,” McManus said in a recent interview.

That didn’t happen.

“It doesn’t make the community feel safer, it doesn’t reduce the number of gunshots in our community,” said William Cruz Shaw, who defeated Warrick in a runoff election for the District 2 council seat. He agrees with the decision not to fund ShotSpotter again. “It doesn’t prevent you from being shot.”

But Ralph Clark, CEO of the Silicon Valley-based ShotSpotter Inc., said San Antonio officials took too narrow of an approach by focusing only on arrests.

Rather, the city should look at ShotSpotter’s other uses, like ensuring police always respond to gunfire, which will reinforce to the community that police care and that gun violence shouldn’t be accepted as the norm.

Officers are more likely to retrieve shell casings if alerted about gunfire, which otherwise might go uncollected, and which can be used for other investigations.

“I think we have a demonstrable track record of working with cities in their gun violence prevention and reduction strategies, using our technologies,” Clark said.

He emphasized that more than 90 U.S. cities use the technology, including Denver, which just expanded its ShotSpotter coverage area.

In just the first two quarters of this year, Denver police said, the department made 18 arrests and recovered 28 guns, with the help of ShotSpotter.

By the numbers

ShotSpotter uses audio sensors to triangulate sound and pinpoint the direction of gunfire. The sound must hit three different sensors before the system will alert police.

Denver launched its program in early 2015. The system has helped officers better identify the location of the gunfire within 25 meters of the source, said Denver Lt. Aaron Sanchez, who oversees ShotSpotter.

That helps, he said, because gunshots often sound like they’re coming from a different direction than they are.

In spring 2016, ShotSpotter was installed in two zones on San Antonio’s East and West sides, where gun violence has been particularly high. Exact locations never were made public.

San Antonio actually extended the program halfway through the fiscal year, in order to adopt a smartphone platform recommended by the ShotSpotter company. That allowed officers to get direct alerts on their phone when gunfire was detected in the designated zones. SAPD dispatchers still assigned officers to the ShotSpotter scenes, Salame said.

The city also assigned a patrol officer in each zone, funded by overtime, to respond only to ShotSpotter alerts and nothing else, between 5 p.m. and 3 a.m.

From the time the program launched May 1, 2016, until May 5 this year, police responded to 785 incidents in the two zones, according to data the San Antonio Express-News obtained through a public records request.

Shotspotter: by the numbers 4 Arrests attributed to ShotSpotter 7 Weapons confiscated thanks to ShotSpotter 55% of the time, ShotSpotter was the only notification police received about gunfire 31% of the time, police learned about gunfire from both ShotSpotter alerts and 911 calls 14% of the time, ShotSpotter didn't work when it should have $546,000 spent on ShotSpotter and police overtime Source: San Antonio Police Department

Of those, police received ShotSpotter alerts — and no 911 calls — 431 times. That means 55 percent of the time, ShotSpotter was the only notification police had that a gun had been fired. More than one ShotSpotter alert might go off for the same incident.

Police could find no evidence of a shooting at the scene about 80 percent of the time, said Joe Frank Picazo, the chief’s assistant.

Officers also found no gunshot victims at any of the ShotSpotter-only incidents, Salame said.

However, the chief said Wednesday residents called police about five homicides in the ShotSpotter zones, but the detection system had not been activated. In about 14 percent of incidents in the zones, a ShotSpotter alert did not go off. Instead, residents notified police about gunfire.

Police received both a ShotSpotter alert and a resident’s 911 call about gunfire in about 30 percent of the incidents in the ShotSpotter zones.

Clark was surprised that people phoned police that often. He has not seen SAPD’s metrics.

“I would really want to understand how you calculated that number,” Clark said.

In terms of arrests, SAPD was very particular about attributing one to ShotSpotter.

If officers were responding to a ShotSpotter alert but then arrested someone at the scene who had an outstanding warrant for another crime, for example, or a resident gave a description of a suspect that helped police arrest him or her, those arrests were not attributed to ShotSpotter.

So, 28 arrests actually were made in the ShotSpotter zones between May this year and last year. But police only attributed four of them to the technology.

How it works in Denver

Denver did not look at its arrests in so narrow a way, Sanchez said.

Denver’s system now covers about 12 square miles, about three times the size of San Antonio’s ShotSpotter coverage area.

But Denver also uses ShotSpotter for other investigative purposes.

The shell casings Denver police collected at ShotSpotter scenes have been traced to other incidents.

Each shell casing is like a fingerprint, indicating a different gun that fired it. Investigators submit the information into the National Integrated Ballistic Information Network, or NIBIN, system. They got 72 NIBIN hits off casings found at ShotSpotter scenes in the first two quarters of the year, Sanchez said. Police have been able to associate those hits with 271 different crimes.

“We use (ShotSpotter) to further other investigations,” Sanchez said. Those ballistic matches can help homicide and gang detectives look “at the big picture of the different crimes, the background of where that gun was.”

ShotSpotter evidence has been used in at least one court case in Denver.

A man claimed he fired on another man in self-defense. But audio from ShotSpotter indicated a five-minute gap between the shots fired. The victim had left the scene to retrieve his gun, returned and then shot and killed the original suspect, Sanchez said.

But a 2016 Forbes magazine article detailing concerns about ShotSpotter noted there are a limited number of instances where the technology has been helpful in court cases.

Salame said San Antonio police have not gotten any ballistic hits on the casings collected at scenes in the ShotSpotter zones. Nor has it been used in any local court cases, to date.

ShotSpotter offered to send one of its analysts to track the ShotSpotter metrics, but the city refused. SAPD tracked the numbers.

“Our people thought it was not appropriate for the vendor to track their own measurements,” Salame said.

Denver did work with ShotSpotter analysts but also tracked the information itself.

Clark, with ShotSpotter, said the company could have done a better job collaborating with SAPD on best practices after installation of the system.

“I don’t know that we ever got on good footing with the department,” Clark said.

The fact that former Councilman Warrick was the program’s biggest advocate may have hurt ShotSpotter, he said, because there wasn’t enough buy-in from the entire council.

At Wednesday’s City Council budget meeting, District 9 Councilman John Courage briefly pushed back on the police chief’s assessment of ShotSpotter, questioning how arrests were categorized. He also wondered if the system might be cheaper the second year in operation.

McManus was unmoved.

“In my opinion, we don’t need any additional research,” he said.

The Police Department plans to use at least some of the ShotSpotter funds to hire eight additional San Antonio Fear Free Environment, or SAFFE, officers for the East and West substation areas.

“We’re going to use that money to provide more community engagement, which ShotSpotter can’t provide,” McManus said recently. “And I believe it will … resonate with the folks who live in those areas a lot more than having some alert go off and police come after the fact.”

San Antonio police cut pricey gunshot detection system

For Rochester police, the gunfire detection system known as ShotSpotter has been a valuable tool, alerting them to possible shootings and speeding up the police response time.

But, more than that, the system — which tries to locate gunfire through audio sensors placed in high-crime areas in the city  — has also become part of courtroom testimony, with prosecutors using the recordings as evidence to bolster their allegations of where and how many shots were fired in criminal incidents.

However, the latter use — evidentiary support for prosecutions — is coming under increasing attack, as critics say the system's use is being stretched beyond its scientifc and analytical limits. The New York City-based Innocence Project, which has helped exonerate nearly 200 wrongly convicted people, recently filed a legal brief in a Rochester criminal case, challenging the reliability of ShotSpotter when it is used for more than a gunfire alert system.

“At the end of the day this is a machine that basically can tell you that there was a loud sound and then a human has to tell you whether it was gunfire or not,” Dana Delger, an attorney for the Innocence Project, said of ShotSpotter in a telephone interview. 

In Rochester, ShotSpotter has been used as proof in several high-profile trials, most notably the trials of the men accused of the shooting in front of the Boys & Girls Club on Genesee Street that left three dead, and the murder of Rochester Police Officer Daryl Pierson by Thomas Johnson III.

The ShotSpotter-captured audio can give a jury a realistic picture of the events of a crime, said Monroe County First Assistant District Attorney Perry Duckles.

"ShotSpotter provides a captured audio of a point in time that we’re trying to explore at any given trial," said Duckles. "When it captures that sound it brings a jury there. It allows them to hear what actually happened the night in question."

With the Johnson trial, prosecutors were able to synchronize the ShotSpotter audio with surveillance videos, giving the jury not only a visual of the fatal shooting of Pierson but also the accompanying sounds of the gunshots.

But some critics see a system that is evolving in court beyond its original purpose of an alert mechanism.

“There’s a few things that are problematic," said Monroe County Assistant Public Defender Katie Higgins, who challenged the use of ShotSpotter audio in a recent criminal trial. "One is that it was designed to be an investigative tool for the police, to alert them to possible gunfire and allow them to respond to see if there are civilian witnesses or other evidence of gunfire.

"But it was not designed to be used as actual primary evidence (in a trial)," she said.

ShotSpotter needs to be subjected to more rigorous testing, from outside unbiased sources, to ensure its accuracy in courts, the critics say.

"While this technology may have advanced to the point where its data can be used as an investigative tool, it is not sophisticated enough to generate data that is reliable enough to be admitted as 'scientific' evidence in a criminal trial," the Innocence Project's Delger wrote in her brief filed in the Rochester case of Silvon Simmons, who was accused of trying to fatally shoot a police officer in 2016.

Alerting to crime

When the city of Rochester first contracted with California-based ShotSpotter in 2006, the company placed its audio sensors — advertised as "gunfire specific acoustic-sensing technology" — in several city areas with high crime rates.

Currently, the sensors cover more than seven square miles of the city, according to Paul Greene, the company's manager of forensics services. Fifteen to 20 sensors are used to cover a single square mile, Greene said in recent trial testimony. 

Rochester now pays $130,000 annually to ShotSpotter, a cost that also includes the testimony at trials.

The sensors are microphones with transmitters attached, and they're located at different elevated spots around the city, ranging from utility poles to privately owned buildings. (ShotSpotter does not publicly release the locations.)

The sounds are transmitted to the company computers, which then studies the audio impulses and the likely distance from the monitoring sensors (at least three sensors need to register the sound for a determination of location). The computers subject the transmitted pulses to algorithms to try to determine the location and source, whether gunfire or something else, such as firecrackers or a backfiring car.  

Those equations then offer a location for a likely shooting incident.

An analyst reviews the audio for "classification verification" — essentially deciding whether the computer was likely correct if it determined the sound was gunfire.

From the sound to notification to a 911 system and police of possible gunfire can take only a minute.

"It's not just a recording at that point," Duckles said. "It's actually a scientific analysis of the recording."

Police or prosecutors cannot make a sweeping request for long swaths of audio, said Special Assistant District Attorney Julie Hahn, who heads the office's major felony bureau and was one of the prosecutors in the Silvon Simmons case. Instead, the company provides the very narrow audio window when shots were fired, which is typically only seconds in duration.

"They will only provide us the pulses, the shots, which occurred with (a particular) incident," she said. Otherwise, Hahn said, the audio could be a privacy breach, possibly capturing snippets of loud street-level conversations or other sounds not connected to an investigation.

The company safeguards its information, and the proprietary relationship with its contracting municipalities gives ShotSpotter a different position than crime laboratories or medical examiner offices whose personnel might testify in a criminal trial about, for instance, forensics or likely causes of death.

A crime lab, for example, is typically a publicly funded operation, and its scientific processes are often an open book for prosecutors, defense lawyers, or forensics experts to explore and dissect for reliability. ShotSpotter officials contend that the algorithms are, like the Colonel Sanders fried chicken recipe, a proprietary company secret.

For defense lawyers, the relationship with the city and ShotSpotter is problematic, blocking them from a review that could show, for example, whether the sensors have been checked or serviced.

ShotSpotter says its research shows that the system is accurate 80 percent of the time within a 25-meter range from a shooting. Critics say that more peer review testing is needed to verify the system's accuracy.

A police shooting

On April 1, 2016, the ShotSpotter sensors picked up several audio bursts from a northwest Rochester neighborhood. Unable through its algorithms to detect a specific location, the system did not alert 911 or police. The system also thought the sounds to be the whirring blades of a helicopter, and not gunfire.

However, that night Officer Joseph Ferrigno chased Silvon Simmons, behind an Immel Street home. Ferrigno said Simmons shot at him once, then Ferrigno fired four shots, hitting Simmons three times.

Simmons was charged with attempted murder of a police officer and criminal possession of a weapon.

Police notified ShotSpotter of the shooting, and the company revisited the audio from the scene. The analysts at first thought there were three shots, then changed to number to four, then five. Analysts found the fifth shot after a prosecution request to review the audio again, prosecutors say.

Simmons' attorneys unsuccessfully sought to have the evidence withheld at trial, claiming that the changes from ShotSpotter officials showed a questionable coziness with authorities and the police version of the shooting. Prosecutors said the audio, once revisited, revealed the clear sounds of five shots.

The evidence was allowed. The jury heard the audio and acquitted Simmons of attempted murder but convicted him of criminal possession of a weapon. The jury may have decided that Simmons had a gun that accidentally discharged, attorneys surmised after the verdicts. 

Attorneys agree that the ShotSpotter audio and testimony that there were five shots were crucial at Simmons' trial.

Because the system relies so heavily on a human review of the computerized data, there is a distinct possibility of "cognitive bias" — a determination that can be influenced by factors other than facts, the Innocence Project argued in the brief it filed in the Simmons' case. 

In its brief, the Innocence Project highlighted the Rensselaer County trial of a man who fired shots at a police officer. In that case, one ShotSpotter analyst heard four gunshots in the captured audio file; another analyst heard three and said the fourth sound was likely a car backfiring. 

The prosecution theory was that three shots were fired. The analyst who agreed with that number overrode the analyst's report of four shots and testified of his conclusion of three shots at the trial.

"This episode shows not only the subjective nature of the determination that a sound is actually the sound of gunfire, but also shows how ... (as here) information from the police may affect the conclusion of the analyst that a particular sound is gunfire," the Innocence Project argued.

Prosecutors say that they typically use ShotSpotter proof as supporting evidence in cases where there is no question a shooting occurred, such as the Genesee Street mass shooting, the murder of Officer Pierson, or the Immel Street shooting that led to Simmons' arrest and trial.

Investigative tool

The worth of ShotSpotter can be tough to argue, with its quick alerts to police of a detected shooting incident. Witnesses have been found and criminal cases solved because of the rapid ShotSpotter alerts. 

While some cities — including Charlotte and Detroit — have abandoned the system, deciding the occasional false-positive alerts were too problematic, many cities, like Rochester, have decided the system is a valuable crime-fighting mechanism.

Almost 90 cities in the United States and elsewhere now use the system, according to the company.

"It's just a great tool to have with its analytics as far as being able to narrow down a (shooting) location," said Lt. Jeremy Lindauer. 

Eric  Piza, an associate professor at John Jay College of Criminal Justice, said that ShotSpotter has been valuable in cities where residents in high-crime neighborhoods have grown inured to the sounds of gunfire and don't always call police.

Piza, who previously worked as a crime analyst with the Newark, New Jersey, Police Department, said that when asked if a locality should use ShotSpotter, his standard answer is, "It depends."

"I think the first important question to ask is what are you trying to get out of this technology," Piza said. " ... The empirical research that has been done on ShotSpotter suggests it might not affect crime reduction."

Piza said he has yet to see research that studies ShotSpotter's reliability when used for specific evidentiary purposes in trials.

ShotSpotter Chief Executive Officer Ralph Clark said the courtroom challenges to ShotSpotter evidence are to be expected, similar to challenges by defense attorneys to most forensics-type evidence.

The challenges are "normal court procedural motions, ones we see repeated time and time again whereby ultimately the evidence was ruled admissible and we testify as experts," Clark said.

Still, those who question the evidentiary use of ShotSpotter data say that judges should subject the company's systems to the same scientific analysis that has been required for the admission of evidence ranging from fingerprints to DNA. And that would require the company to open its system to outside review.

At Simmons' trial, ShotSpotter forensics service manager Greene said of the company, "We're not required to have peer review but we're open to it."

Assistant Public Defender Higgins said she hopes that day comes.

"It needs to be ... generally accepted within a wider scientific community," she said.

Is shot spotter reliable enough? Critics question human equation behind technology

The Fall River Police Department and ShotSpotter, the $120,000-a-year gunshot detection system, have officially parted ways.

FALL RIVER - The Fall River Police Department and ShotSpotter, the $120,000-a-year gunshot detection system, have officially parted ways.

The California-based company decided it could no longer offer its service to the city for free after police and administration officials balked at funding a system that they said worked less than 50 percent of the time and even missed all seven shots that were fired when a man was killed two months ago in downtown Fall River.

“The company had asked for the chance to bring it up to par where we needed it to be, but we saw little improvement with it in the past eight or nine months,” said Fall River Police Chief Al Dupere.

ShotSpotter shut the system off a few days ago following a meeting last week between a company representative, Dupere and Mayor Jasiel Correia, who criticized the company for “walking away” instead of keeping the system in place and working to improve it.

“I told them I was disappointed in ShotSpotter. I told them it’s a shame for them to not at least use Fall River for publicity while they tried to make their product work as best they could,” Correia said, adding that the system for now is not worth the investment.

“It’s a costly system that isn’t working to the effectiveness that we need it to work in order to justify the cost,” Correia said.

A ShotSpotter media representative was not immediately available for comment.

Since last July, when Dupere first told ShotSpotter that he no longer planned to continue using its service, the company had kept the system live in Fall River, free of charge to the city, while trying to work out the shortcomings.

Dupere said last summer that ShotSpotter had reported too many false alarms of gunfire while missing actual shots-fired incidents in Fall River. Dupere said then that he and other city officials decided the money would be better used to expand the police department’s video surveillance system in the city.

But ShotSpotter offered to improve the system and work with the city to secure grant funding, prompting local officials to re-embrace the technology.

“We are pleased with the response from ShotSpotter to our concerns,” Dupere said this past December.

Four months later, however, Dupere said ShotSpotter has not improved. He told the Herald News that the system has about a 50 percent accuracy rate; far below the 90 percent mark the city was promised when it signed with the company five years ago. Dupere said ShotSpotter also missed all seven shots in the Feb. 14 murder of Maurice Timberlake, who was gunned down at the corner of South Main and Morgan streets.

“Even if nobody had gotten hit, it still missed all the gunshots,” Dupere said. “That’s what we’re paying them for.”

ShotSpotter also only detected only one of the three shots-fired calls earlier this week in the Flint and Niagara neighborhoods, officials said.

“We are not interested in paying $120,000 a year, which is police officers, which is cameras, which is vehicles, for something that works less than 50 percent of the time,” Correia said.

Dupere said last week’s meeting with ShotSpotter was prompted by the city’s decision not to include funding for ShotSpotter in the next fiscal year that begins on July 1.

When local officials announced in October 2012 that Fall River would become the fifth city in Massachusetts to adopt ShotSpotter, the technology was hailed as an effective crime-fighting tool that would enable police officers to respond to shooting scenes quicker, interview witnesses sooner and arrest suspects that could otherwise get away.

The system was advertised as being able to report the number of gunshots, the caliber of weapons used in a shooting, the direction of gunfire and even the shooter’s movement, and to relay all that information almost in real-time to police dispatchers.

While other communities have reported using it relatively well, the system in Fall River never operated smoothly. Dupere said the city was told that the system was capable “of doing things it just couldn’t do.”

Dupere said ShotSpotter has left its sensors in place throughout Fall River in the event that future technological upgrades allows the company to make its system work in the city.

“I’m open to it, if in the future improvements are made,” Dupere said. “But right now, it doesn’t make sense. It’s just not working for us.”

After too many shots missed, Fall River officially ends deal with ShotSpotter

MacArthur Justice Center study finds City’s use of ShotSpotter is inaccurate, expensive and dangerous

CHICAGO – A new study of Chicago’s use of ShotSpotter, a surveillance system designed to detect gunfire, finds that the vast majority of alerts generated by the system turn up no evidence of gunfire or any gun-related crime. Instead, the ShotSpotter system sends police on thousands of unfounded and high-intensity deployments, which are focused almost exclusively in Black and Latinx communities. The complete findings of the study can be found at EndPoliceSurveillance.com.

“Surveillance technology has a veneer of objectivity, but many of these systems do not work as advertised, ” said Jonathan Manes, an attorney with the MacArthur Justice Center, who spearheaded the study. “High-tech tools can create a false justification for the broken status quo of policing and can end up exacerbating existing racial disparities. We needed to know whether this system actually does what it claims to do. It does not.”

ShotSpotter blankets neighborhoods with microphones in order to attempt to detect and locate the source of gunfire. It sends alerts of supposed gunfire immediately to local police. ShotSpotter claims to be 97% accurate. However, ShotSpotter has not released any scientifically-valid study to substantiate that figure. There are also no studies testing whether ShotSpotter can reliably tell the difference between the sound of gunshots and other noises like firecrackers, backfiring cars, construction noises, helicopters, and other loud, impulsive sounds.

The study conducted by MacArthur Justice Center at Northwestern Pritzker School of Law reviewed ShotSpotter deployments for roughly 21 months (from July 1, 2019 through April 14, 2021) using data obtained from the City of Chicago. Their analysis found that 89% turned up no gun-related crime and 86% led to no report of any crime at all. In less than two years, there were more than 40,000 dead-end ShotSpotter deployments.

“Our findings are shocking,” said Manes. “The ShotSpotter system in Chicago prompts thousands of deployments by police hunting for gunfire in vain. This system puts police on high alert and sends them racing into communities; but almost nine times of our ten, the police don’t turn up evidence of gun crime or any crime at all. It creates a powderkeg situation for residents who just happen to be in the vicinity of a false alert.”

The study is also the basis of an amicus brief filed today in support of a motion by the Cook County Public Defender that challenges the scientific validity of the ShotSpotter system’s gunfire reports, which prosecutors have attempted to use as evidence in a criminal prosecution.

The amicus brief was submitted on behalf of a coalition of community-based organizations that are concerned about the impact of ShotSpotter on overpoliced and underresourced communities of color on the city’s South and West sides. Those organizations are Brighton Park Neighborhood Council, Lucy Parsons Labs, and Organized Communities Against Deportations (OCAD).

“Knowing very well that police officers tend to escalate all types of situations and are known to use excessive force, the ShotSpotter technology creates an additional layer of violent response from police officers as they rush aggressively to poor, Black & brown neighborhoods expecting to be met with gunfire,” Miguel Lopez, Membership Coordinator for OCAD. “If the city was really serious about stopping gun violence, they would listen to the community and use those $33 million dollars to invest in those communities in order to create the social environment where young people would have the transformative tools to deal with conflict.”

The City of Chicago has deployed ShotSpotter only in the police districts with the highest proportion of Black and Latinx residents. On an average day, there are more than 61 ShotSpotter-initiated police deployments that turn up no evidence of any crime, let alone gun crime. Neighborhoods that are surveilled by ShotSpotter are subject to thousands of additional, unfounded police deployments just because the ShotSpotter system is present.

Every unfounded ShotSpotter deployment creates an extremely dangerous situation for residents in the area. ShotSpotter primes police to believe that they are heading to a dangerous location where a person has just fired a gun. Any resident who happens to be in the vicinity of a ShotSpotter alert will be a target of police suspicion or worse. These volatile deployments can go wrong in an instant.

“Only residents in predominantly Black and Latinx neighborhoods have to contend with the burden of thousands of unnecessary and potentially dangerous police deployments,” said Manes. “Only their neighborhoods get saddled with inflated statistics about supposed gunfire. At the same time, there is no evidence that the ShotSpotter system makes communities safer or reduces crime.”

CPD publicly promotes ShotSpotter as an essential tool for crime prevention, but there is no evidence that it reduces crime. Academic studies of ShotSpotter and similar gunshot detection systems have found that they do not reduce the number of violent crimes and do not even reduce the number of confirmed shooting incidents identified by police. Instead, the studies find that the main effect of ShotSpotter is just to increase the number of times police are deployed.

The Chicago Police Department has a long history of excessive force, illegal and discriminatory stop-and-frisk, and other abusive policies and practices. ShotSpotter reinforces and may exacerbate this system of racialized policing.

CPD requires managers to incorporate ShotSpotter data into its CompStat reports, which are used to hold commanders accountable to performance targets. ShotSpotter data also feed into the city’s “predictive policing” technology. The inflated gunfire statistics generated by ShotSpotter in predominantly Black and Latinx neighborhoods will thus skew how the police allocates its resources, unless the city is taking careful steps to eliminate the effects of unfounded ShotSpotter alerts. These statistics can create a false “techwash” justification for racialized patterns of policing.

“Like many surveillance systems, CPD’s use of ShotSpotter trades on a veneer of objectivity but, in practice, it reinforces racial disparities in policing,” said Manes. “The City should be investing in communities and in solutions that work, not in police technologies that create faulty justifications for ever more policing.”

In 2018, the City of Chicago entered a $33 million, three-year contract with ShotSpotter. Over the past two years, the City has paid ShotSpotter about $10 million per year and spends untold additional resources on police officers chasing down tens of thousands of unfounded ShotSpotter alerts every year. The City of Chicago is one of ShotSpotter’s two largest customers, accounting for 18% of its annual revenue in 2020. The City of Chicago’s contract with ShotSpotter expires August 19, 2021 unless the city exercises its option to extend.

The complete findings of the study, including the legal brief filed in court, can be found at EndPoliceSurveillance.com.

ShotSpotter Generated Over 40,000 Dead-End Police Deployments in Chicago in 21 Months, According to New Study

The New York City and Chicago police departments spend millions of dollars a year on gunshot detection technology that a privacy group argues is ineffective and invasive.

The departments pay ShotSpotter Inc. for technology that uses microphones and audio software to identify the sounds of gunshots in neighborhoods. But the technology hasn’t made an impact on gun violence and typically doesn’t result in investigatory leads, according to a new report from the Surveillance Technology Oversight Project, a nonprofit privacy organization.

“Americans are desperate to feel safe, but we have to look at what surveillance companies are really selling us,” the group’s executive director, Albert Cahn, said in a statement. The microphones pick up sounds other than gunshots, including voices, according to the report, adding: “This technology is worse than a gimmick, it can put people in harm’s way.”

If ShotSpotter detects that a gun has been fired, it ascertains the location of the sound, isolates it and compares it to previous gunshot sounds before sending it to a human technician who performs a review. If the technician believes the sound is an actual gunshot then the police are alerted.

The company says more than 200 jurisdictions use its products around the world, many of which are US cities and towns. Both New York and Chicago are key customers however, accounting for nearly half of the company’s first quarter revenue this year, according to filings with the US Securities and Exchange Commission. The cities have contracted with the policing technology company for at least five years. Chicago added an additional year and $5.7 million to a contract with the company that could be worth as much as $33 million, while New York signed on for a $22 million contract in December that extends through 2024, according to city procurement records.

ShotSpotter said in a statement that the technology makes communities safer by solving cases, saving lives and deterring crime. The report “is simply a rehash of previous false and misleading allegations,” the company said. “The report is not presenting any new information and only serves to undermine the critical work ShotSpotter is doing to combat gun violence and save lives.”

In a statement, the New York Police Department called ShotSpotter “a highly effective crime-fighting tool,” adding that “false positives” are not passed along to officers. The Chicago Police Department said in a separate statement that “gunshot detection technology has detected hundreds of shootings that would have otherwise gone unreported.”

“CPD receives real-time alerts of detected gunfire, enabling patrol officers to arrive at a precise location of a shooting event quickly,” according to the statement. “This allows law enforcement to respond more quickly to locate and aid victims, identify witnesses, and collect forensic evidence.”

Yet the report argues that the technology brings a heightened police presence to neighborhoods with little to show for it in the end. New York and Chicago have been grappling with an increase in shootings since the onset of the coronavirus pandemic, which has not slowed even as they renewed contracts with ShotSpotter this year, according to city procurement data.

An audit of the technology done by Chicago’s Office of Inspector General last year found that of the more than 50,000 ShotSpotter alerts for probable gunshots, only 9.1% resulted in evidence of a gun-related offense. The report went on to conclude that the product had little operational value for police, given that it rarely produced evidence of a gun crime, an investigatory stop or the recovery of a firearm. The audit did find that police were more likely to stop people based on the frequency of ShotSpotter alerts.

The company typically deploys the microphones in areas that police and other city officials deem hotspots for shootings and violence. Microphones are then placed on streetlights, buildings and utility poles, according to the report.

In response to the Chicago audit, ShotSpotter said “many factors” could lead to the lack of evidence of a gun-related crime and that its findings did not speak to the product’s accuracy.

The nonprofit’s report also raised privacy concerns around the company’s microphones, which record audio on a rolling 30-hour basis. Because the system consists of microphones and recording software, it can pick up other sounds during normal operations. The Legal Aid Society raised issue with the potential for the company’s products to serve as a “massive eavesdropping device.”

ShotSpotter said in its statement that the “risk of sensors picking up human voices is extremely low.”

It’s not clear if the company would turn over recordings other than gunshots or what data is kept on its servers. A representative did not comment on that process.

ShotSpotter has publicly defended itself from allegations that its devices lead to bad community outcomes, filing a defamation suit against Vice Media in October over news reporting about the company’s involvement in an arrest. It vehemently maintains that it plays no role in decisions to arrest, charge or prosecute individuals.

NYC, Chicago Waste Millions on Gunshot Detection Technology, Report Says

Syracuse, N.Y. – A report came out last week that criticizes gunshot detection technology used by cities across the country - including Syracuse - as ineffective, wasting officers’ time and targeting overpoliced communities.

The Surveillance Technology Oversight Project (STOP) released the report questioning the usefulness and cost of ShotSpotter, a gunshot detection technology used by police to try to identify and locate shots fired within certain areas.

Syracuse police and the Onondaga County District Attorney’s Office officials, however, say Shotspotter has been a crucial tool in investigating shootings, in trials and in allocating officers since it was installed in 2017.

“It is a tool in the toolbox,” said Syracuse police Lt. Matthew Malinowski. a spokesperson for the department. “There is no one solution to really combat gun violence.”

The report’s major criticisms of Shotspotter are:

  • It wastes officers’ time by prompting a response to shots fired calls that cannot be verified or are not gunfire.
  • It doesn’t result in more arrests or convictions.
  • It increases policing in historically overpoliced neighborhoods.
  • Microphones can record conversations of people in these neighborhoods.

In the report’s conclusion, STOP argues that there is not enough evidence that the technology effectively combats gun violence and it says cities should consider reinvesting the money to combat the root causes of gun violence.

Despite criticisms, ShotSpotter is becoming more prolific in the United States. As of March 2022, the technology is used in at least 130 U.S. cities and towns, a 50% increase from 85 cities in 2018, according to the report by the New York City-based non-profit organization.

Many cities, including Syracuse, invested money from the American Rescue Plan Act to install or expand the program. In 2021, Syracuse used $171,000 from the act to expand the technology into the city’s North Side.

Each year, the city spends just under $400,000 on the technology, Malinowski said.

ShotSpotter uses microphones installed in certain areas of the city and audio software to try to identify potential gunshots. When a sound that may be a gunshot is registered by multiple microphones, a technician at the company will listen to the recording and verify whether it is a gunshot in under 60 seconds, according to ShotSpotter’s website.

Once the sound is verified as a gunshot, the acoustic waves are triangulated and provide police with a location, the company said. The alert is sent out to police, either through 911 dispatches or an app on the officers’ phones.

Inaccurate, waste of time or helpful tool?

The report states that ShotSpotter has inaccuracies in its characterization of loud noises as gunshots and its location data.

The accuracy of the location varies, Onondaga County Chief Assistant District Attorney Shaun Chase said. Chase said that sometimes the system works like “find my iPhone” while other times it only provides a general area.

Malinowski said this is a major improvement when compared to shots fired incidents reported by citizens. Often people will report hearing gunshots a few blocks away which leads to larger crime scenes and more time spent searching for evidence, he said.

Chase confirmed that sometimes sounds such as cars backfiring of fireworks could be mistaken for gunshots, but he said the same issues can arise when police rely on citizen reporting.

Malinowski said that sometimes gunshot reports are ruled unfounded when no casings are found, but that is not a confirmation that no shots were fired in the area.

Malinowski said he does not have the data to accurately describe the number of false reports by the system. He said he believes that despite the kinks in the system, the data provided is still invaluable to police.

When police rely solely on citizens, many shots-fired incidents and shootings go unreported, Malinowski said. According to the ShotSpoters website, around 80% of shots fired incidents are unreported.

Helps arrests, convictions?

Another major concern raised in the report is the lack of evidence collection and arrests that stem from the deployment of officers to shots fired notifications, according to the report. According to a study of major cities utilizing the technology cited by the report, only one arrest is made for every 200 notifications.

In an analysis of 50,000 ShotSpotter notifications in Chicago, 244 arrests were made and 152 guns were recovered according to the report. In Brockton, MA, the technology increased police activity but did not improve gun-related case resolutions, the report says.

Malinowski said that although not every investigation leads to an arrest, the technology has been very helpful in locating guns utilized in multiple crimes.

Police often collect casings that match those connected to other investigations, this helps investigators build cases and track down new leads on weapons that are being repeatedly used for violence, Malinowski said.

Once arrests are made, the recording of gunshots provided by ShotSpotter can prove to be crucial in criminal trials, Chase said.

The DA’s office frequently uses the recordings as evidence, Chase said. He said it is much more compelling to play the audio of the gunfire for a jury rather than have an evidence technician describe the scene.

In some cases, the recordings can speak to motives in a crime, Chase said. Proving intention in shooting or homicide trials requires many factors. Chase used self-defense cases as an example.

When a defendant is asserting self-defense, listening to the cadence of gunfire can inform investigators and a jury, he said. When a recording shows a short and rapid exchange of gunfire, that can point to a case of someone acting to defend themselves, he said. In contrast, if there are numerous shots fired over a long period of time by one person, that can indicate the action was intentional, he said.

It is not the “smoking gun” but it can be a crucial piece of the evidence presented, Chase said.

Overpoliced communities targeted, report says

STOP argues that the historic overpolicing of these communities has produced crime data that disproportionately represents violence in these communities.

In Syracuse, Shotspotter covers about 2.1 square miles of the city’s North Side centered around Lodi Street, Butternut Street, North Salina and parts of James Street and Teal Avenue, according to Chase and city officials.

The technology also covers about 3.5 square miles of the South Side, primarily centered around South Geddes Street, Malinowski said.

Both Malinowski and Chase said that the report’s assumptions ignore other socio-economic factors that lead to higher crime, such as poverty.

The data provided by ShotSpotter can inform police what areas experience higher volumes of gunshots to better allocate officers, Malinowski said.

Are mics recording people?

As a surveillance oversight project, one of the STOP report’s largest concerns is the capacity for the ShotSpotter microphones to record conversations. The report argues that this is an invasive technology because the microphones are recording at all times.

According to the report, a ShotSpotter engineer testified to the NYC Committee on Public Safety that the microphones have the potential to record conversions at a normal volume from up to 50 feet away.

In 2007, a California court accepted a voice recording captured by ShotSpotter microphones as evidence in a murder trial, according to the report. In 2019, the company agreed to deny or challenge police demands for audio recordings that do not include gunshots on the recommendation of external auditors, according to the report.

In Syracuse, police and investigators only receive the audio that includes gunshots, Chase said. Occasionally, screams and shouts are picked up in this audio but they are often inaudible, he said.

On Thursday, Chase reviewed the last 12 recordings that were attached to notifications of shots fired in the ShotSpotter app, he said. The longest of those 12 recordings was six seconds long, he said.

Law enforcement officials are not being provided with extensive clips of the audio recordings that would allow them to listen to conversions even though the microphones are capable of that, Chase said.

ShotSpotter’s responds

Simone Jackenthal, a spokesperson for ShotSpotter, said that the STOP report presents misleading allegations.

Over 80% of shots-fired incidents go unreported, so the company’s system provides police departments with faster response times and accurate incident locations, Jackenthal said.

An independent review determined that the system has a 97% aggregate accuracy rate, Jackenthal said. ShotSpotter can notify police of nearly all outdoor gunfire, she said.

In reference to privacy concerns, Jackenthal said that ShotSpotter has been independently audited multiple times. Oakland’s Privacy Advisory Commission has unanimously approved the use of ShotSpotter twice, she said.

Report: ShotSpotter wastes officers time, provides little help in court, targets overpoliced communities

(TNS) — A report came out last week that criticizes gunshot detection technology used by cities across the country - including Syracuse - as ineffective, wasting officers’ time and targeting overpoliced communities.

The Surveillance Technology Oversight Project (STOP) released the report questioning the usefulness and cost of ShotSpotter, a gunshot detection technology used by police to try to identify and locate shots fired within certain areas.

Syracuse police and the Onondaga County District Attorney’s Office officials, however, say Shotspotter has been a crucial tool in investigating shootings, in trials and in allocating officers since it was installed in 2017.“It is a tool in the toolbox,” said Syracuse police Lt. Matthew Malinowski. a spokesperson for the department. “There is no one solution to really combat gun violence.”The report’s major criticisms of Shotspotter are:

  • It wastes officers’ time by prompting a response to shots fired calls that cannot be verified or are not gunfire.
  • It doesn’t result in more arrests or convictions.
  • It increases policing in historically overpoliced neighborhoods.
  • Microphones can record conversations of people in these neighborhoods.

In the report’s conclusion, STOP argues that there is not enough evidence that the technology effectively combats gun violence and it says cities should consider reinvesting the money to combat the root causes of gun violence.Despite criticisms, ShotSpotter is becoming more prolific in the United States. As of March 2022, the technology is used in at least 130 U.S. cities and towns, a 50% increase from 85 cities in 2018, according to the report by the New York City-based non-profit organization.

Many cities, including Syracuse, invested money from the American Rescue Plan Act to install or expand the program. In 2021, Syracuse used $171,000 from the act to expand the technology into the city’s North Side.

Each year, the city spends just under $400,000 on the technology, Malinowski said.ShotSpotter uses microphones installed in certain areas of the city and audio software to try to identify potential gunshots. When a sound that may be a gunshot is registered by multiple microphones, a technician at the company will listen to the recording and verify whether it is a gunshot in under 60 seconds, according to ShotSpotter’s website.Once the sound is verified as a gunshot, the acoustic waves are triangulated and provide police with a location, the company said. The alert is sent out to police, either through 911 dispatches or an app on the officers’ phones.Inaccurate, waste of time or helpful tool?The report states that ShotSpotter has inaccuracies in its characterization of loud noises as gunshots and its location data.The accuracy of the location varies, Onondaga County Chief Assistant District Attorney Shaun Chase said. Chase said that sometimes the system works like “find my iPhone” while other times it only provides a general area.Malinowski said this is a major improvement when compared to shots fired incidents reported by citizens. Often people will report hearing gunshots a few blocks away which leads to larger crime scenes and more time spent searching for evidence, he said.Chase confirmed that sometimes sounds such as cars backfiring of fireworks could be mistaken for gunshots, but he said the same issues can arise when police rely on citizen reporting.Malinowski said that sometimes gunshot reports are ruled unfounded when no casings are found, but that is not a confirmation that no shots were fired in the area.Malinowski said he does not have the data to accurately describe the number of false reports by the system. He said he believes that despite the kinks in the system, the data provided is still invaluable to police.When police rely solely on citizens, many shots-fired incidents and shootings go unreported, Malinowski said. According to the ShotSpoters website, around 80% of shots fired incidents are unreported.Helps arrests, convictions?Another major concern raised in the report is the lack of evidence collection and arrests that stem from the deployment of officers to shots fired notifications, according to the report. According to a study of major cities utilizing the technology cited by the report, only one arrest is made for every 200 notifications.In an analysis of 50,000 ShotSpotter notifications in Chicago, 244 arrests were made and 152 guns were recovered according to the report. In Brockton, MA, the technology increased police activity but did not improve gun-related case resolutions, the report says.Malinowski said that although not every investigation leads to an arrest, the technology has been very helpful in locating guns utilized in multiple crimes.Police often collect casings that match those connected to other investigations, this helps investigators build cases and track down new leads on weapons that are being repeatedly used for violence, Malinowski said.Once arrests are made, the recording of gunshots provided by ShotSpotter can prove to be crucial in criminal trials, Chase said.The DA’s office frequently uses the recordings as evidence, Chase said. He said it is much more compelling to play the audio of the gunfire for a jury rather than have an evidence technician describe the scene.In some cases, the recordings can speak to motives in a crime, Chase said. Proving intention in shooting or homicide trials requires many factors. Chase used self-defense cases as an example.When a defendant is asserting self-defense, listening to the cadence of gunfire can inform investigators and a jury, he said. When a recording shows a short and rapid exchange of gunfire, that can point to a case of someone acting to defend themselves, he said. In contrast, if there are numerous shots fired over a long period of time by one person, that can indicate the action was intentional, he said.It is not the “smoking gun” but it can be a crucial piece of the evidence presented, Chase said.Overpoliced communities targeted, report saysSTOP argues that the historic overpolicing of these communities has produced crime data that disproportionately represents violence in these communities.In Syracuse, Shotspotter covers about 2.1 square miles of the city’s North Side centered around Lodi Street, Butternut Street, North Salina and parts of James Street and Teal Avenue, according to Chase and city officials.The technology also covers about 3.5 square miles of the South Side, primarily centered around South Geddes Street, Malinowski said.Both Malinowski and Chase said that the report’s assumptions ignore other socio-economic factors that lead to higher crime, such as poverty.The data provided by ShotSpotter can inform police what areas experience higher volumes of gunshots to better allocate officers, Malinowski said.Are mics recording people?As a surveillance oversight project, one of the STOP report’s largest concerns is the capacity for the ShotSpotter microphones to record conversations. The report argues that this is an invasive technology because the microphones are recording at all times.According to the report, a ShotSpotter engineer testified to the NYC Committee on Public Safety that the microphones have the potential to record conversions at a normal volume from up to 50 feet away.In 2007, a California court accepted a voice recording captured by ShotSpotter microphones as evidence in a murder trial, according to the report. In 2019, the company agreed to deny or challenge police demands for audio recordings that do not include gunshots on the recommendation of external auditors, according to the report.In Syracuse, police and investigators only receive the audio that includes gunshots, Chase said. Occasionally, screams and shouts are picked up in this audio but they are often inaudible, he said.On Thursday, Chase reviewed the last 12 recordings that were attached to notifications of shots fired in the ShotSpotter app, he said. The longest of those 12 recordings was six seconds long, he said.Law enforcement officials are not being provided with extensive clips of the audio recordings that would allow them to listen to conversions even though the microphones are capable of that, Chase said.ShotSpotter’s respondsSimone Jackenthal, a spokesperson for ShotSpotter, said that the STOP report presents misleading allegations.Over 80% of shots-fired incidents go unreported, so the company’s system provides police departments with faster response times and accurate incident locations, Jackenthal said.An independent review determined that the system has a 97% aggregate accuracy rate, Jackenthal said. ShotSpotter can notify police of nearly all outdoor gunfire, she said.In reference to privacy concerns, Jackenthal said that ShotSpotter has been independently audited multiple times. Oakland’s Privacy Advisory Commission has unanimously approved the use of ShotSpotter twice, she said.

Report Evaluates Efficiency of Gunshot Detection Technology