The use of federal security screeners at air ports and transport hubs is an interesting proposition and a hotly contested subject. For the most part it appears to be junk science. However, used in conjunction with voice stress analyizers could be both deceptive on the surface and far more efficient than plain screeners.
During the early 80s while I was working in El Salvador, the chief of Salvadoran intellegence asked me to attend a sales pitch by an American company that wanted to sell the El Salvadoran army some Voice Stress analysiers.
A part of the sales pitch was that major banks were using them in an internal security capacity and customs was using them at selected points of entry. The story line went that there was a hidden microphone and a few innocent questions would be asked to establish a truth graph of sorts and then came the loaded question: are you smuggling drugs, are you steeling from the bank etc. That was the story line and I have no idea if they were bought or the validity of the science but it could very well be the surface debate is missing the dynamics be they already tested or being tested of a voice stress analyizer or some like device.
The spin of is how this will find its way into the streets for the local police to use in taking action against the local population. Just the thought of being approached by a police officer in a suspecious manner will certainly elevate the stress level know that the basic philosophy of innocent till proven guilty in a court of law is a vanishing piece of Americana that has become “let’s make a deal.”