CAMBRIDGE, Mass. — If you heard gunshots echoing through Cambridge on Tuesday night, don't be alarmed.
Cambridge Police were testing out their 'ShotSpotter ' system, a technology that alerts police to gunfire as soon as shots are fired.
The testing phase of the technology is important to ensure it can quickly detect gunfire and determine exactly where it's coming from. In an active shooter situation, law enforcement say minutes and even seconds count in their response.
When it's set up correctly, ShotSpotter technology can be very accurate. Police are able to learn where exactly a gun was fired and at what time of day.
"It takes less than a minute, where if we have gunshots in an area and we don't have an officer in the area sometimes it's proven that after we get the ShotSpotter it's not until 5, 6 minutes later that we get a 911 call," said Cambridge Police Detective Superintendent Steve Ahren.
Officers spent the afternoon and evening testing out the system over and over again in different locations in the city.
Acoustic systems placed throughout different neighborhoods can detect the sound of a gun being fired and immediately triangulate the shooter's location.
The sound is also recorded and sent back to a command center, where a trained person will listen to it and determine if it's actually gunfire and what kind of gun was used.
"Then they send us the data and we get it on our mobile devices, officers get it inside the cruiser and the communications center gets it as well," Ahren said.
ShotSpotter technology can also determine the threat level based on what the shots sound like.
"If we didn't have this system the officer would be going into an unknown situation," said Ahren. "The officer wouldn't know where the shot came from or how many shots there were."
In Cambridge, a 1.25-mile radius is covered with the system.
So far, there have been eight shootings in the city within the last year - where 6 happened within the area covered by ShotSpotter. The system picked up on 5 of those shots.
"Nothing is 100% accurate or guaranteed, but it is a tool in our toolbox," said Ahren.
On Wednesday evening, police departments in Chelsea, Everett and Revere will also be testing out their ShotSpotter sensors.
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