According to CBS News, some British scientists have invented a video lie detector. No wires, no mess - it just records a subject and uses software to analyze facial movements. I'm skeptical about it, but they claim to have an eighty percent success rate. I suspect it will have the same pros and cons as the polygraph. IMO, it will catch most guilty people, but not psychopaths or those who have been trained to fool it. However, the main problem with these types of devices is that they also 'catch' innocent nervous people who just look guilty. If you read the article carefully, it says it can detect lies 80% of the time. Great! But I want to know the rate of false positives; that is, how often does it say an innocent person is lying? The article is silent on that point and CBS apparently didn't think to ask the question.