NEWPORT NEWS, Va. (WAVY) — In Newport News and in Virginia Beach, when no one dials 911, police can rely on technology such as the ShotSpotter system, which alerts police to the sound and location of gunfire.

ShotSpotter has been around for decades but is relatively new in Virginia. It keys on vibration the same way scientists detect earthquakes. Two local police chiefs swear by it, but some cities have dropped it.

Newport News Police Chief Steve Drew would be the first to let you know that his city is on track for far fewer shootings this year compared with last year. But in just a 10-day span last month, the city’s ShotSpotter system got horribly busy.