NEW YORK (CBSNewYork) -- The NYPD has a new device to help find weapons.

WCBS 880's Stephanie Colombini reports the hand-held detectors silently flash a red light and vibrate around potential weapons, alerting police without the suspects noticing.

A source told the New York Daily News that it's not uncommon for officers to miss something small – like a box cutter or blade – when they're frisking someone.

The NYPD conducted a pilot program with the portable detectors in 10 precincts in Brooklyn last April.

Police did not provide any statistics on how many weapons the devices found, but the program's apparent success led officials to expand use of the detectors citywide.