NYPD begins testing long-distance gun detector as alternative to...

As part of its ongoing effort to keep New York City safe, the NYPD has begun testing a new scanning device capable of detecting concealed firearms from a distance of about 16 feet.

Developed in conjunction with the Department of Defense, the technology uses terahertz imaging detection to measure the radiation that humans naturally emit, and determine whether the flow of this radiation is impeded by a foreign object -- in this case, a gun.

During a...