New Report on Gunshot Detection Tech: “there is not enough evidence that the technology effectively combats gun violence”

By B.N. Frank

Despite inaccuracies and high costs as well as privacy and safety concerns, ShotSpotter (see 1, 2, 3) and other gunshot detection technology continue to be installed, operated, and expanded in American communities. Now another report suggests THAT it’s NOT effective and it may be wasting police officers’ time.

From GovTech:

Report Evaluates Efficiency of Gunshot Detection Technology

A report came out last week that criticizes gunshot detection technology that is used by cities across the country as ineffective, wasting police officers’ time and targeting overpoliced communities.

Anne Hayes, syracuse.com

(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 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.