Aside from traffic and noise, big cities tend to be plagued by crime. When Mike Bloomberg was mayor of New York City, he turned to high tech solutions in the form of the Domain Awareness System (DAS). Now, under Mayor Bill de Deblasio the city is expanding on that with a system for alerting police in real time to gun shots.
Like several other American cities associated with gun violence, New York tried out ShotSpotter in a pilot program. It rolled out on March 16, 2015, in the Bronx and was set to cover five zones of three square miles each in that borough and in Brooklyn.
New York's press office explained how the technology would aid police:
The ShotSpotter system triangulates the location of a gunshot to within 25 meters of where the shot was fired. The system then forwards a notification to an incident review center where a trained operator reviews the audio file to determine if the sound was that of a gunshot or some other similar-sounding audio incident (e.g. fireworks, engine backfiring, etc.). Once the incident is determined to be a gunshot, an alert is sent to the NYPD via the Domain Awareness System (DAS). This alert includes relevant information such as number of shots fired, location of the gunshot (including map access), if the shooter was moving at the time of the incident (such as in a vehicle), and the direction of the shooter’s movement. Upon receipt of such an alert, the NYPD can dispatch units to the location of the shooting.
Equipped with that information, the police would be able to get to the site of the shooting without delay. A faster response could potentially save the life of victims and also increase the odds for catching the shooter if only by finding witnesses to the crime. The alerts also make police aware of shots that would never get reported otherwise.
That’s part of the case that ShotSpotter makes for its product: that less than 20% of shootings are called in on 911. That’s pretty close to what New York found in its pilot program. ShotSpotter revealed that between 75 and 80 percent of shots were never called in. The NBC News reports that the NYPD attributes eight arrests and 13 gun recoveries in 2015 directly to Shot Spotter, as there were no 911 calls placed in connection to those incidents.
Considering ShotSpotter to be a valuable addition to the NY police force, the mayor announced an expansion of the ShotSpotter program. At the same press conference, the NYPD’s Deputy Commissioner of Information and Technology Jessica Tisch, said that in addition to placing sensors in more areas, they would also make use of mobile technology, delivering the system’s alerts “directly to the smart phones and tablets of officers in the vicinity.”
New York would be the first city to implement this direct communication in place of a centralized dispatch system. The idea behind it is that the bit of extra time saved will make responses even faster “and presumably increase apprehension and evidence recoveries.” The idea is that police in the area would get the notification “within seconds of shots being fired” and also would have access to the audio file and information about the location in which it occurred.
While no one would argue that we shouldn’t take steps to prevent crime, some do argue that ShotSpotter is not the way to achieve it in a cost-effective way. Are we getting more bang for the buck, or paying more bucks for the bangs? That’s the gist of the argument in ShotSpotter not exactly taking a bite of our crime: “Take San Francisco, for example, where there were more than 3,000 ShotSpotter alerts over a two-and-a-half-year period. Of those, two resulted in arrests. And only one was gun related.”
However, a very different picture is presented in ShotSpotter: An Alternative Viewpoint. In addition to crediting the audio obtained from it with warding off a riot based on the misperception that police fired on an unarmed teen, the writer insists it plays a significant role in the 50% reduction in the murder rate in the years following its installation in the area. He also insists, "Shooters were caught. I know shooters were caught, because since moving there I had been on the SFPD Bayview Station’s e-mail list and had religiously read the twice-weekly crime and police reports … I started actually seeing arrests for the gunfire, not just mentions of incidents of gunfire."
Certainly, the cities that continue to invest in it do believe in the value of the technology. ShotSpotter is expanding pilot programs into new locations, like San Antonio. The local news there reported that it is showing some effect just weeks after it was implemented.
So is it effective or not? It all depends on what you apply as your metric of success. If getting police alerted about a shot is your metric, then it is clearly is effective. However, if you want to see a significant increase in arrests for gun violence, you may not consider the increases there to be worth the investment.