Lie Detector

[driverdale1]

If you do a minor crime under the influence of smoking drugs and claim not to remember doing that crime, would it then not show up under a lie detector if asked due to the fact that he cannot remember doing it?

[woofgang]

I am not sure what you are asking? but the way lie detectors work is by recording heightened stress cause in most people by telling the lie. If you don’t feel the heightened stress for whatever reason then the lie detector won’t pick it up.
http://www.livescience.com/33512-pass-lie-detector-polygraph.html

[Buenchico]

As Woofgang states, so-called 'lie detectors' are really stress detectors. Anyone who is asked to take a lie detector test under the circumstances you describe would almost certainly already have been accused of committing the crime. Therefore, if he genuinely can't remember what he was doing at the time of the alleged offence, he's likely to experience stress (through confusion, as he tries to recall what actually happened) when he's again asked about it under test conditions. That could occur whether or not he'd actually committed the offence, meaning that he'd appear to be lying in either case.