Manchester police chief believes gunshot technology delivers bang for the buck
May 17—It's a quiet Saturday evening on Manchester's West Side when gunfire splits the silence.
At police headquarters, the department's ShotSpotter map registers multiple gunshots near a Coolidge Avenue address. Officers respond, arresting 47-year-old Adam Rousseau on six counts of reckless conduct for allegedly firing six rounds over a nearby homeless encampment.
But it's the ensuing search of the man's residence — resulting in the seizure of six rifles, three handguns and an assortment of ammunition — that shows the gunshot detection system is giving the city its money's worth, according to Manchester's top cop.
"We didn't get any 911 calls — or any calls — from residents in the area," Police Chief Allen Aldenberg said. "Officers get a location, go out there, start knocking on doors, they knock on this guy's door and he tells them, 'Yeah, I ripped off six rounds.' That's a win.
"The arrests we make on shootings that we may never have been notified about — to me, that's worth it."
ShotSpotter technology uses a series of small audio sensors positioned high atop light posts and buildings. When a gun is fired, the sensors triangulate on the sound, pinpointing the number of shots fired and their location.
The vast majority of gunshots detected by the controversial police surveillance tool do not result in an arrest, but Aldenberg said ShotSpotter sensors are helping to drive down the number of shootings in the city.
"I think it has benefits," Aldenberg said. "I think the benefits outweigh the negatives right now. It's not a perfect tool, but what technology is?"
Technology under fire
Other cities across the country aren't as sure.
In Chicago, the city's inspector general reported officers who respond to a ShotSpotter alert find no evidence of a shooting more than 90% of the time. In 2022, the organization Surveillance Technology Oversight Project cited studies that found that nationally, for every 200 times ShotSpotter is activated, one arrest results.
In 2022, Manchester police received a federal grant of $300,000 to cover the cost of acquiring and implementing ShotSpotter for a two-year trial across a 3-square-mile section of the city. An undisclosed number of sound-sensitive devices are deployed in the city's East and West Side neighborhoods. Aldenberg won't say exactly where.
Since the system went live in April 2023, Aldenberg said, the system has been activated 257 times by possible gunfire.
Of those, Aldenberg said, 36 were confirmed shooting incidents, and 92 were false positives. Another 113 were classified as "undetermined," after police responded, investigated and were unable to confirm shots were fired.
Aldenberg also noted nine "false negatives" — shooting incidents that police responded to based on calls to the dispatch center but that never generated a ShotSpotter alert.
"What I like about the ShotSpotter is we're being alerted quicker to potential gunfire or gun crimes," Aldenberg said. "What I mean by that is, we had multiple instances where ShotSpotter alerted us directly to our dispatch, in to my officer in charge, over five minutes before we got the first 911 call. "
Aldenberg said the system also gives his officers "as much knowledge as they can get" going into a call involving gunfire.
"When you look at ShotSpotter and the rounds go off, it gives you almost a direction of travel," Aldenberg said.
"When they're responding, they get it right on their phone and dispatch can tell them it looks like the shots were going in a westerly direction — so that when we get there, they're going in with as much information as we can give them, hopefully to keep them alive, too."
More gun seizures
As of mid-May, Manchester police had seized 67 guns this year, compared to 23 over the first 4 1/2 months of last year, Aldenberg said. In 2023, the city reported a 27% reduction in gunfire incidents.
"To me, that's a significant number of arrests and guns that are off the street that we never would have got," Aldenberg said.
While Manchester is the only department in New Hampshire to deploy ShotSpotter, the technology is used in several cities in Massachusetts including Boston, Springfield, Somerville and Worcester.
The ACLU of Massachusetts has called the technology ineffective, saying it threatens basic civil rights.
In an email, an ACLU-NH spokesperson declined comment on Manchester's use of ShotSpotter. Manchester NAACP President James McKim also declined comment, saying his organization plans to meet with the police department in June to discuss the technology.
In a letter dated May 14, U.S. Sens. Ed Markey and Elizabeth Warren and Rep. Ayanna Pressley of Massachusetts and U.S. Sen. Ron Wyden of Oregon asked Joseph V. Cuffari, inspector general of the Department of Homeland Security, to open an investigation into his department's grant-funding of ShotSpotter "to determine whether it is an appropriate use of taxpayer dollars."
ShotSpotter's website denies claims that "coverage areas are biased, lead to over-policing or potentially dangerous police deployments in Black and Latinx communities."
Aldenberg said locations for ShotSpotter sensors in Manchester weren't chosen at "random."
"This is where the data told us where the vast majority of our shootings were taking place, in the areas where we now have coverage, so I don't buy that argument from the ACLU," Aldenberg said. "So those people in those neighborhoods, where these shootings were happening — they don't deserve some type of additional policing method to hopefully improve those neighborhoods?"
Justifying the effort
Aldenberg said his department reviews data to determine whether the technology should be deployed elsewhere.
"Six months from now or a year from now we can say, 'Hey, we've accomplished what we needed to accomplish in the areas where we're having problems and now maybe we have another area — say, the South End — where all of a sudden we see a spike in shootings over time, not just one-offs or anomalies, but some consistent shooting behavior,'" Aldenberg said. "We would look at that and say, 'We need to move some sensors or do we need to buy more and invest in more?'"
The guns Manchester police have seized "were in the hands of prohibited people," Aldenberg said. "Those were in the hands of people that are possessing drugs. Those were in the hands of felons. Those are the people that are bringing harm to this community and those are the people that shouldn't have guns.
"I can't see how anybody would want to make a logical argument against that."
Despite intensified scrutiny of ShotSpotter, Aldenberg says it is worth the money, particularly considering the arrests in shootings that may never have been reported.
"That's nine arrests that potentially we never would have made, evidence that we've been able to recover and link to other shootings," Aldenberg said. "We've recovered casings here that we've connected to shootings in Nashua, shootings in Connecticut."
Federal funding for ShotSpotter run out next spring. In his proposed fiscal year 2025 budget, Manchester Mayor Jay Ruais included $300,000 to keep it running.
Aldenberg hopes aldermen agree and will fund the system in their soon-to-be-revealed budget.
"I don't see them (aldermen) getting away from it, because I think at the end of the day, it is making the city safer," Aldenberg said. "It's just one part of everything else we're doing.
"If that part was to go away we'd still be working hard, but I would hate to take away something that has allowed us to make the arrests that we've made that we wouldn't have probably made."
