Polygraph Evidence in Georgia Criminal Cases: Is it Admissible in Court?

False accusations occur every day in the State of Georgia and across the country.  In many false allegation cases, only the accused and the alleged victim know what really occurred, and the outcome of the case may depend entirely on the credibility of the witnesses.  A polygraph, or lie detector test, conducted by a respected polygrapher can tip the scale in favor of the accused, and as a result, it can act as a powerful tool in convincing a prosecutor not to bring charges, to reduce charges, or to dismiss charges altogether well before trial.  In some cases, the results of a polygraph may also be used in a criminal trial to help prove an individual’s innocence.

Whether an individual should undergo a polygraph is a decision that should be made only after consulting with an experienced criminal defense lawyer.  A criminal defense lawyer will have the knowledge and expertise to know if a polygraph will be beneficial in a specific case.  The lawyer will also know which polygrapher is right for the job depending on the county or jurisdiction where the investigation or charges are pending.

Polygraphers used by criminal defense lawyers are typically individuals who formerly worked for government agencies such as the Georgia Bureau of Investigation or the Federal Bureau of Investigation and are well respected in their field.  The cost of a polygraph depends on the polygrapher that is used and the depth of questioning that is required.  Typically, the cost can range anywhere from a few hundred dollars to more than two thousand dollars.

A polygrapher measures and records physiological changes in the body such as pulse, blood pressure, and respiration during questioning.  From these physiological changes, the polygrapher will determine whether the individual is being truthful, lying, or if the results are inconclusive.  Inconclusive results can occur in many situations such as when the individual is under a great deal of stress and the polygrapher is unable to differentiate between a truthful answer and a lie.  If this occurs, more than one testing session may be required.

The results of a polygraph can always be used to assist in convincing a detective or a prosecutor to terminate an investigation or to drop a case if charges have already been filed.  At trial, however, polygraph results are only admissible under certain conditions.  If the trial court is not convinced that the conditions have been met, the jury will never know that an individual underwent a polygraph examination.

In 2013, Georgia adopted the Federal Rules of Evidence to replace most of its evidentiary rules, and the Georgia appellate courts have yet to rule on when polygraphs are admissible under the new rules.  Under the old rules, polygraph results were admissible when the prosecution and the defense stipulated to the admissibility of the results.  Generally, the prosecution will only stipulate to the admissibility of the results if 1) the polygraph has yet to be performed; 2) the prosecution agrees to the polygrapher to be used ; and 3) the prosecution agrees to the questions to be asked.  This is always a risk, because if the results end up favoring the prosecution’s case, the prosecution can introduce the results at trial.

It is very likely that Georgia courts will look to the federal courts for additional guidance on when polygraphs are admissible.  The Eleventh Circuit Court of Appeals has held that polygraph evidence is admissible in two specific instances: 1) where both parties stipulate in advance as to the circumstances of the test and as to the scope of its admissibility; and 2) when used to impeach or corroborate the testimony of a witness at trial.  To be admissible to corroborate or impeach, there are three additional requirements: 1) the defense must provide adequate notice to the prosecution; 2) the prosecution must be provided a reasonable opportunity to have its own polygraph expert administer a test covering the same questions; and 3) the polygraph evidence must satisfy the admissibility requirements of the Federal Rules of Evidence.

The third requirement is by far the most difficult for a defense lawyer to overcome.  Evidentiary rules require that the trial court act as a gatekeeper of scientific evidence such as polygraph testing.  The court must determine whether the expert’s technique or theory can be or has been tested; whether the technique of theory has been subject to peer review and publication; the known or potential rate of error of the technique or theory; the existence and maintenance of standards and controls; and whether the technique or theory has been generally accepted in the scientific community. In other words, the trial court must focus on the principles and methodology and not the conclusions reached.  Together, these factors are known as the Daubert factors.

Because polygraphs are typically viewed as an “inexact science”, trial courts are hesitant to allow the results into evidence and often find that the defense has not satisfied the Daubert factors.  A trial court may also prevent polygraph evidence from being admitted in a criminal trial by finding that the prejudicial effect of the evidence substantially outweighs its probative value and that the polygraph evidence will otherwise only serve to confuse the jury.

Stipulating to the admissibility of a polygraph will most likely remain the most viable option for introducing polygraph results into evidence during a criminal trial.  Due to the inherent risks of such stipulations, the decision should only be made after careful consideration and advice from an experienced criminal defense attorney in Georgia.


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