Nopoly:
But the opinion comes with a lot of wieght and expierence my friend. Assuming the history of a LEO polygrapher. That person is a detective, or a an experienced Special Agent. More then likely with a degree in psychology and has a tremendous amount of expierence in interviewing and interrogation. He/She will use all of that knowledge and expierence to make the best decision possible. Will they make a mistake, sure. Hec, I've made them too. But I had probable cause to do the things I did. Was I wrong for the mistake. It just didn't work out that time. However the next officer that felt the same way I did got the goods (lucky bas*&^%).
I've been fortunate to have skilled, and ecellent interrogators who polygraphed me. When I've talked to other VSA/Polygraphers, I get the same answer. They hate each other, but at the same time they won't make a determination until after reading the charts, looking at the video, and listening to the recording. Once they have the totality of the situation they'll make there judgement. Meaning you could use countermeasures during a polygraph. But those darn NVI's you can't mask can and will fail you.
I've never gone through any type of polygraph training. Again, thats interview/interrogation 101.
If a subject keeps telling me no no no, but his NVI's are showing me yes yes yes. Am I gonna stop asking? Will I believe his no's. I stated to painful the other day, I'm skeptical as soon as I hear I'm a religous person. So, are priests who committed sexual abuse on minors, or jihadists blowing things up.
Am I synical? Nah... I have a job to do.
I've heard that polygraphers are lying about how the machine detects lies. Well, no polygrapher has ever told me that. It shows your BP, respitory, and sweatiness etc etc. However again it's the totality of the situation that will dictate that a person could POSSIBLY be deceptive. However without a confession, then it's only possibly. For prescreeners unfortunatly that could be enough NOT to get a job (which is why I don't like them), but at the same time there are a literally thousands of LEA's throughout the country. If your a criminal, and you go tightlip afterwards, well I'd say thats a clue. I guarantee the investigators will be working harder to complete the job.
Mr. Johnston: nice analagy... Please again as a polygrapher let me know if I'm not writing this impartially...