What to Do If Asked to Take a Lie Detector Test

If you’ve watched crime dramas on TV, you are probably familiar with the general concept of a lie detector test. Basically, a polygraph works by measuring your body’s physiological response to certain questions asked of you. The general philosophy is that your body will have obvious natural responses if you give an answer you know to be false.

The test measures your pulse, blood pressure, sweat levels, breathing rate and other responses. The tester begins by asking a series of questions and will analyze your responses while you answer the questions. Theoretically, increased levels of the above factors indicate a greater likelihood that a person is lying.

Admissibility of polygraph evidence

The problem with polygraphs is that the evidence they produce is not exactly conclusive — some people respond to polygraphs in different ways than others. For this reason, the results of polygraph tests are usually not admissible in court, which can make their findings rather useless.

Still, it is important to remember that the entire purpose of a lie detector test is to collect evidence against you, whether it comes from pre- or post-test questions or the actual test results. Everything about a polygraph is designed to work against you, so even if the court bars evidence from a test for submission in a trial, the statements you make could still benefit the prosecution.

Therefore, you are likely better off avoiding polygraphs whenever you have a choice. It’s also not typically recommended to take a polygraph to prove your innocence.

For further advice and guidance when you are facing criminal charges in Pennsylvania, speak with experienced Reading criminal defense lawyer David R. Eshelman.