There are 35 shot spotters all over East Palo Alto. Just about every corner of the city is covered. The technology can pick up gun fire from more than a mile away, which will help on New Year's Eve.
The sound of gunfire isn't extraordinary in East Palo Alto, especially on New Year's Eve.
"People use poppers, they noise makers, unfortunately we have people who also incorporate fire arms into that celebration, which is very, very dangerous," said East Palo Alto police Det. Sgt. Jeff Liu.
That's why East Palo Alto police will triple patrols on Saturday night and keep extra eyes on its ShotSpotter system.
Police demonstrated how it works on Thursday. Officers fired several rounds off Weeks Street. That shot spotting device, roughly 100 yards away, picked up the sound and notified police. A red dot on the system shows authorities exactly where the shots came from and even records the sound.
On New Year's Eve, officers will already be staging in ShotSpotter hot spots.
"Any ShotSpotter activations, we're going to be on top of very quickly and rapidly," said Liu.
Just two weeks ago, the ShotSpotter system alerted police to a shooting on Gonzaga Street. A 19-year-old was killed that day. ShotSpotters are also in Redwood City -- the first city in the country to adopt the program. And it too has an ongoing problem with New Year's Eve gunfire.
"Obviously anytime anyone fires guns into the air, those bullets have to come down and they do come down in the same communities where these people are firing their weapons," said Redwood City Police Sgt. Ashley Osborne.
Studies show 80 percent of the time, no one ever reports hearing gunshots. That was incentive enough for the creators of ShotSpotter.
"We're basically providing that missing link all the time, we're always on, for a very quick, very precise," said Ralph Clark, President of ShotSpotter SST Inc.
Celebratory gunfire was a much bigger problem in the early 1990s. But because of "Operation Silent Night," which includes extra volunteer patrols, things are getting better. In 2010, Redwood City had 22 reported incidents, but even one is too many.
"Simply, it's a dangerous practice and there's no reason for it," said Osborne.
Besides Redwood City and East Palo Alto -- Richmond, San Francisco, Oakland and East Palo Alto also use the ShotSpotter system.
Firing a gun into the air is a felony. If you are convicted of discharging a firearm, you could face up to three years in prison.
Some cities have set up hotlines you can call if you hear gunfire in your neighborhood.
The Redwood City Police Department has established a hot line for members of the public to report gunfire: 650-780-7639.
In East Palo Alto, residents can call the police department at 650-321-1112 to report gunshots.