"If something is obstructing the flow of that radiation - for example, a weapon - the device will highlight that object," NYPD Commissioner Raymond W. Kelly said at the Police Foundation's State of the NYPD breakfast, according to the New York Times. "This technology has shown a great deal of promise as a way of detecting weapons without a physical search."
The new device, developed in conjunction with the Pentagon, is currently effective only at short ranges of three to four feet. But NYPD spokesman, Paul J. Browne, said he was confident that the range could be extended to 82 feet. With that kind of distance, officers could conduct infrared friskings from their squad car.