Terahertz? It’s killing me! But that’s what the new scanners the NYPD is testing use to see whether or not someone’s packing heat. More specifically, it looks for the outline of something blocking the body’s natural emissions of terahertz radiation — something shaped like a gun perhaps. This, from nydailynews.com: “The department will begin testing the high-tech device for use on the street. The device is small enough to be placed in a police vehicle or stationed at a street corner where gunplay has occurred in the past.” The new equipment won’t be used to scan people about to board planes. No, the new gizmos are intended to peer at (and under the clothing of) anyone walking down the street, minding his or her own business. Mayor Mike and his army appear ready to turn the Big Apple into a giant Fourth Amendment-free zone. Alan Gottlieb, please call your office.