The Plainfield (N.J.) Police Department is the latest agency to consider using a technological system called ShotSpotter that uses audio freqencies to pinpoint the location where shots were fired.

The system is in use by more than 50 law enforcement agencies around the country.

Agencies using ShotSpotter, according to the manufacturer, say it reduces violent crime, discourages random gunfire, aids in arrests, provides data for investigations and prosecutions, and has allowed agencies to refocus patrols in critical areas of the city at certain times.

The Plainfield (N.J.) Police Department is the latest agency to consider using a system that has been adopted in Boston, Los Angeles, Minneapolis, D.C. and Birmingham (Ala.), reports MyCentralJersey.com .

Gunshot detection is possible with the system that involves the installation of small auditory sensors—16 per square mile—in areas where gunfire is more common.

When a gun is fired, sound waves travel outward in all directions at a uniform speed, hitting the sensors at different times. Those times are then compared digitally to determine the origin of the shot with sharp accuracy.

According to the company, in 2006, 91 percent of gunshots recorded by active ShotSpotter systems were pinpointed to within 10 meters of an actual firing location. The sensors are so sensitive, they can help determine the number of shots fired, whether a shooter was moving when firing, and the caliber of weapon used.

The system reduces the frequency of gun shots essentially by increasing police response time, because shots-fired data is relayed to responding officers within seconds, according to the company.

"Faster police time means quicker arrests, shorter investigations and a smarter use of our resources in Minneapolis," according to Councilman Gary Schiff . "With five to six thousand reports of shots fired in the city each year, hopes were high that the city would see a dramatic reduction in violent crime."

In one dramatic instance in the metro D.C. area, ShotSpotter data was responsible supporting the accounts of two officers accused of an improper shooting.