I wrote back in November 2013 about ShotSpotter—a network of acoustic sensors that tries to detect and locate gunshots in an urban environment.
Just yesterday, the Daily News reported that New York City Police Commissioner Bill Bratton said the ShotSpotter technology would be used in conjunction with GPS systems installed in the city’s police vehicles to allow the prompt dispatch of officers to the scene of gunshots.
And in February, SST, the company that makes ShotSpotter, announced that the technology has been deployed in 90 cities worldwide, having added Denver, Detroit, Pittsburgh, Savannah/Chatham, Trenton, and Cape Town to its roster in the second half of 2014. “The unique real-time gun crime intelligence we provide helps local agencies offer a higher quality of service to many underserved communities,” said Ralph A. Clark, SST president and CEO. “As a result community support and law enforcement collaboration increases thereby deterring and preventing gun crime.”
But the technology may have downsides. Writes Lee Fang at The Intercept, “Critics worry that the microphones are prone to false alarms, and more troubling, appear to vacuum up street-level conversations in the neighborhoods where it has been installed. Evidence from conversations recorded by ShotSpotter microphones has been used to prosecute criminals in court.”
The latter appears to refer to the arrest of a man for murder in 2011 in New Bedford, MA, based on an audio recording of a street argument.
Regarding that incident, Brian Fraga of SouthCoast Today quoted Lydia Barrett, a spokeswoman for ShotSpotter, as saying the sensors are designed to detect the acoustic signature of a gunshot. “This is a very unusual circumstance if (the sensors) actually picked up any voices,” Fraga quoted Barrett as saying. “In particular, I can’t ever remember in the history of our technology the sensors ever hearing a fight or some kind of argument going on.”
False alarms can certainly be a problem, especially if, as Sarah Gonzalez of WNYC reported in 2013, 75% of gunshot alerts in Newark were false alarms. As for the legitimate alerts, she quoted a police sergeant as saying, “Usually when we get there, the perp is not in the area.” Perhaps the New York City approach of using ShotSpotter in conjunction with GPS will help with this.
But as for the privacy issue—even if ShotSpotter can record voices, I’m not sure this raises a red flag for me. You can hardly have a presumption of privacy if you are arguing in the street.