If I Take a Polygraph Test, Can I Show the Judge or Jury the Results?

January 28, 2010

By Bob Coleman,

Coleman, Chambers & Rogers, LLP


If I want to increase my credibility at trial, should I take a polygraph so that the jury knows I'm telling the truth? What are the rules involving lie detector tests in the courtroom?

That's a question we're often asked by clients who, understandably, want to do whatever it takes to prove their sincerity and credibility to a jury. Sometimes it's someone wanting their spouse to take questions about an affair. Sometimes it's the spouse volunteering to take a polygraph to show they have nothing to hide. Sometimes people just want so badly for the judge or jury to believe that they are telling the truth, they want to do whatever it takes - like sit for a polygraph - to bolster their side of the story.

But with one major exception, polygraph results are not admissible evidence in Georgia for either civil or criminal trials. And because they're usually not admissible, it means the judge or jury never learns the result or even hears that someone took a test. So the fact someone passed, failed, or even took a polygraph exam is usually of little consequence at trial.

Why is that?

Georgia courts, like courts in a number of states, are concerned the tests are too unreliable. So for decades polygraph results have not been admissible evidence in Georgia courts. And because jurors may feel otherwise about the reliability of polygraph tests, the courts don't want cases to hinge on who passed or failed a lie-detector test. Georgia courts are so concerned about polygraph evidence unfairly influencing a jury (lawyers and judges refer to this as "prejudicing the jury"), even mentioning that a witness took a test, or refused to take a test, can result in a mistrial or appeal.

So you can never admit polygraph evidence, even if both party's want to?

That has to do with the one major exception I referred to earlier. Georgia law provides that polygraph tests can be admitted if both parties in the case agree, in advance, that a witness will take a test and the results will be shown at trial. This is known as a "stipulation." However, given the possibility of unreliable results, many attorneys will not agree to this even if their clients request it and are adamant they are telling the truth. If there is any chance, however slight, that the test showed a negative result on a key question, it could ruin the witness's credibility forever in the eyes of a judge or jury.

Another exception relates to passing references to polygraph tests that don't suggest the results. Merely mentioning a test may be allowed in court, so long as it isn't clear to the judge or jury whether the test was passed or failed. For example, a witness on the stand might say, "I took an hour off of work to go by the police station to take a polygraph test." A judge may allow this statement on the grounds it does not suggest whether the witness passed or failed the test, or even whether they had a choice in taking it.

However, even an innocent mention of a test like this could have a dangerous effect on the outcome of a case. The way another judge may see it, the fact the witness volunteered information that he or she took a polygraph is an obvious inference that the witness passed the test.

The same goes for testimony that someone refused to take a test. The judge might see it as an attempt to persuade the jury to infer that the person who refused the test has something to hide and isn't trustworthy. If the judge feels this testimony is too prejudicial, it could result in a mistrial, or opposing counsel may use it for a basis for an appeal.

So to answer your question, polygraph tests are usually only admissible if you have a pre-trial agreement with the opposing party to allow a test and the results admitted into evidence. This is a decision that you can not take lightly, and your attorney will have to carefully weigh the pros and cons of anyone involved in the trial taking such a test.