Takes all sorts, personally I like to meet characters who may or may not be what they profess to be!

Have you tried this "polygraph" thing on yourself?

Can you back that up?

He doesn't have to.

You are the one claiming Polygraph works.

It's up to you to prove it works.

Well, good job there arent too many serial killers around.

Perfectly innocent people who are simply nervous might fail the test, even though they're telling the truth. Alternatively, accomplished liars might not show any signs of stress when lying, even though they are hooked up to the polygraph. For example, the serial killer Gary Ridgway, also known as the Green River Killer, was questioned about his early murders under polygraph observation. Ridgway passed the polygraph test and was released. He then proceeded to claim many more victims before being convicted.

How would a polygraph in Thailand fare under the defamation rules - if the polygrapher uncovers that someone is lying couldn't the loss of face be grounds for defamation given the truth is not a defence here?

Polygraph testing is not "lie detection". Anyone operator of the device that makes such a claim is not a professional.

The polygraph is supposed to record physiological characteristics when the subject is questioned. It is hypothesized that most subjects will exhibit certain physiological characteristics when they engage in deceptive behavior. However, in any given population physiological characteristics shake out on a Bell Curve. In plain language, some people will appear to be lying, when they are not and others will appear to be truthful when they are not. In the middle of the results pool will be that big bump who demonstrate physiological results consistent with "lying". Fortunatey, the courts take into account the unreliability of the testing and do not accept polygraph results.

Sounds like you are more private investigation who also can do lie detection.

when I think lie detection test I think of Robert Deniro giving Focker his test "cause you dont wanna be outside the circle trust Focker"