Christchurch private detective offering lie detector test which is unlikely to work

The prevailing scientific opinion on lie detector tests is that they don't work well enough to be relied on in courts as evidence - in fact, they're probably not even a good way of discerning the truth. Unfortunately a Christchurch based private detective is selling tests to couples as a way of finding out whether a partner has cheated.

Lie detector tests measure biometric indicators, and this particular test (the Lafayette LX5000) measures breathing, heart rate, blood pressure and finger sweating. Barry Newman claims a 96% accuracy for his testing, a value he seems to base on a cherry picked study.