The NYPD expects to receive more reports of shots being fired after the rollout early Monday of the ShotSpotter system to detect gunfire, Commissioner William Bratton said.

At a joint news conference with Mayor Bill de Blasio announcing a $1.5 million pilot program of 300 acoustical sensors covering 15 square miles of the city, Bratton said the plan was to have the system operate for a year in some of the areas of the Bronx and Brooklyn with a high incidence of gunfire.

ShotSpotter devices will cover areas of 17 precincts -- 10 in Brooklyn and seven in the Bronx -- and will be tied into the NYPD's vast Domain Awareness System, which uses other technology for rapid assessment of developing crime situations, Bratton said.

photosRecent NYC mug shotsDataNYC crime rates

The program became operational in the Bronx shortly after midnight on Sunday. Brooklyn is expected to follow in about a week, Bratton said. Several Long Island communities use the system.

"In terms of getting an accurate picture of what is happening, this will assist us significantly and my expectation is shots fired reports will go up," Bratton said, adding the data would be used to help the department try to predict where certain violent crimes will occur. "Where we put in ShotSpotter we know it's going to make a difference," de Blasio said of the constant sound of gunfire which plagues certain neighborhoods.

The program, which the NYPD has been testing since 2011, is being expanded at a time when, through March 15, the city had 185 shooting incidents compared with 166 last year, an increase of 11.4 percent, the latest NYPD statistics show.

advertisement | advertise on newsday

Shootings reported weekly by the NYPD cover only those instances in which someone is injured by gunfire, according to a police official familiar with the record keeping. Records of "shots fired" incidents are kept separately and until now have relied largely on 911 calls to get police involved, Bratton said.

Sounds picked up by the acoustical sensors are first relayed to ShotSpotter Inc. corporate headquarters in California, where experts quickly decide if they are actual gunshots and not other sounds, Deputy Commissioner Jessica Tisch said. Confirmation of a gunshot is then relayed to the NYPD, which dispatches patrol cars, she explained.

During demonstration of the technology before the pilot program started, reporters heard sounds of three shots fired in Brooklyn over the weekend and saw an overlay of video images from the area of the address pinpointed. The first 911 call came in two minutes later and led to a dispatch of police cars, but no ballistic evidence was recovered, Tisch said.