Concealed Weapon Detector to be Deployed in the U.S?

I’ve seen the concept on TV a couple of years ago, but apparently, the U.S government is purchasing twelve concealed weapons detectors from QinetiQ. This particular one seems to be based on microwaves that detect things that are denser than human flesh and clothes, but I have not seen the detailed specs (more information on QinetiQ’s site).

There is also competing system that works by recognizing the magnetic signature of weapons logged in a database.