Since lying does not produce a measurable physiological response -- and hence renders 'lie detection' meaningless -- the plausibility of the theory of so-called lie detection tests is questioned. Empirical evidence is presented that disputes the accuracy of testing and shows the high rate of false positive misclassification (e.g., misclassifying a truthful person as deceptive). An alternative procedure is recommended. This procedure, sometimes called the Guilty Knowledge Test, has some problems associated with its use and can be used only when particular information is available. However, it can be a significantly more accurate detector of guilt than the standard lie detection test. (Publisher abstract)