Police in New York City are going to be trying out a series of sensors that identify gunshots and alert officers, a system that has been used in cities across the country to try to speed up the law enforcement responsible to shootings.

New York City Mayor Bill de Blasio (D) and Police Commissioner William J. Bratton announced the pilot program on Monday, saying that it would be tested in the Bronx and Brooklyn. The first system was activated in the Bronx on Monday, while the Brooklyn system will be turned on next week, the police said.

ShotSpotter has been deployed in cities like Washington, D.C., Denver and Oakland, Calif. It uses a series of sensors to pick up gunfire and pinpoint the area where the shots occurred. In addition to alerting police, it can be used to figure out where shootings may occur down the line.

“It will enable us to respond to shooting incidents in a more timely manner, and provide us with the ability to help victims, solve crimes and apprehend dangerous suspects more quickly,” Bratton said in a statement Monday.

Bratton was on the board of ShotSpotter, which is based in California, until he was hired for the New York City job. De Blasio had said during his mayoral campaign in 2013 that he wanted to use technologies like ShotSpotter, and Bratton told the New York Times after he was appointed that he and de Blasio “never had a conversation about ShotSpotter.”

There will be about 300 sensors active in the two boroughs as part of the pilot program. This program will cover about 15 square miles, accounting at the outset for a small fraction of the city’s 302-square-mile span. Last year, the police said they were seeking a two-year contract for a “demonstration project,” and if it were successful, the system would be expanded over a larger area, according to a notice submitted to the City Record. If the program is viewed as a success, it could also help shed light on the true number of shootings that take place in the city.

So far this year, there have been more than 160 shooting incidents in New York City, up 21 percent from the same period last year, according to the police department. But these numbers are inevitably incomplete, as there are gunshots that are simply not reported to authorities.

In Washington, for example, the number of gunshots found by SpotShotter was greater than the number of officially reported felony gun crimes by a margin of more than 2 to 1. Systems like ShotSpotter can also pick up the other noises that commonly populate cities, like fireworks, though its sensors are intended to ignore these other sounds.