New York: Comptroller voices criticism of gunshot detection technology

New York City
Police officers reportedly spend several hundred hours a month investigating false alarms from ShotSpotter. (Source: Dllu – CC BY-SA 4.0)

The New York City comptroller has found evidence of the unreliability of the controversial gunshot detection system ShotSpotter and questioned the continued use of the technology. An audit report published on June 20 reveals that the system produces a substantial number of false alarms. Police officers are often dispatched to locations only to determine that no shots have been fired. “During the sampled months of review in 2022 and 2023, ShotSpotter alerts only resulted in confirmed shootings between 8% and 20% of the time,” the report states.

In June 2023 for example the New York Police Department (NYPD) responded to 940 alerts issued by ShotSpotter. In 82 percent of cases, the officers who arrived at the scene could not confirm shootings. In 5 percent of cases the alerts were unfounded, and only in 13 percent did a shooting incident actually take place. In the months reviewed for the audit, the number of alerts that led to confirmed shootings was never higher than 20 percent. Nevertheless, the system achieved its contractually obligated performance goals in almost all police precincts – because the goals were set so low.

Comptroller Brad Lander said in a press release: “The evidence shows that NYPD is wasting precious time and money on this technology and needs to do a better job managing its resources. Chasing down car backfires and construction noise does not make us safer.”

ShotSpotter can purportedly detect, locate, and alert law enforcement to shootings in public areas – and do so automatically. In order to pick up suspicious noises, microphones are installed on fixtures like streetlights across entire neighborhoods or even entire cities. The system then uses algorithmic analysis to determine whether the sounds are actually gunshots and not other noises, like fireworks. If the software flags a sound as suspicious, employees listen to the recording – and alert the police if they believe the alert is justified.

A waste of time

The unreliability of the system results in police officers spending lots of time chasing down false leads, according to the audit: In June of last year officers spent 427 hours investigating alerts that did not lead to confirmed shootings. “Spread across a year, this potentially represents significant waste of officer hours,” the report states. “This in turn has fiscal consequences which the City can ill-afford.”

Nevertheless, “NYPD does not currently track the amount of time – or the associated staff costs – spent responding” to false alarms, the report states. The department did not respond to a request for comment from the New York Times. A spokesperson for the mayor’s office said in a statement, “While we understand that emerging technologies evolve and there is always room for improvement, what seems to be lost on the comptroller is that ShotSpotter has given the NYPD the ability to solve countless crimes and save lives.”

SoundThinking, the company that owns ShotSpotter, issued a statement in response to the report, claiming that its findings “show a lack of understanding of public safety operations in the field.” The comptroller’s audit “uses the wrong metrics” to evaluate the success of the system, the company said.

Risk of discrimination

Scholars and civil liberties groups have repeatedly voiced concerns about ShotSpotter. In April an investigation by the American Civil Liberties Union Massachusetts (ACLUM) concluded that “ShotSpotter is an unreliable technology that poses a substantial threat to civil rights and civil liberties, almost exclusively for the Black and brown people who live in the neighborhoods subject to its ongoing surveillance.”

Critics call attention to the fact that false alarms – like fireworks or other loud noises – can lead to a disproportionately heavy police presence in flash-point neighborhoods, since officers are dispatched even when no crime has been committed. In February Wired magazine published a list of sensor locations – which was confirmed by SoundThinking as accurate. The list shows that the sensors are installed “primarily in low-income communities of color.” Civil liberties groups have long pointed out that victims are subject to unjustified police actions simply because the sensors are installed in their neighborhoods.

In light of the criticism, a group of three US senators and one representative sent a letter to the Department of Homeland Security in May of this year demanding that it review its funding of ShotSpotter and investigate whether the use of the controversial surveillance technology has led to civil rights violations.

Other cities end use

Numerous cities across the US have already stopped using ShotSpotter and allowed their contracts to expire, the New York Times reports. In one incident in Chicago, an unarmed 13-year-old boy was shot and killed by police officers after the system issued a false alarm. Mayor Brandon Johnson promised after the killing to get rid of ShotSpotter. In Boston the system has also fallen in for criticism after the letter from congressmembers demanding an investigation into its use.

Since the NYPD began using ShotSpotter in 2014, the city has paid 45 million dollars to California-based SoundThinking, with an additional 9 million still left on the contract. More than 2,000 sensors are currently installed in the city.

The NYPD’s contract with ShotSpotter will expire in December. The comptroller recommends that the contract not be renewed until the system can be fully evaluated. “NYPD’s data collection should be improved, analyzed more critically, and published in the interest of transparency,” the audit states. “The data currently collected and published by NYPD does not support a comprehensive assessment of the tool’s effectiveness or economy.” (hcz)