BBC: Police consider lie detector tests
Police in the North West could soon use lie detection tests to interrogate suspects… The Silent Talker device has been developed in the region and is touted as having a 90% success rate.
As opposed to tossing a coin, which has a 50% success rate.
Come to think of it, how do you measure the accuracy of a lie detector? If the subject knows it's just an experiment, they'll probably behave differently to people who are genuinely being interrogated. And, if the subject doesn't know it's just an experiment, there must be some independent means of measuring whether they're lying, which presumably must be 100% accurate… So why not use that method to interrogate suspects in the first place?
Lie detectors in Blighty, I ask you. IS THIS WHAT GRANDAD FOUGHT THE NAZIS FOR?