How do defense attorneys use polygraph evidence in Georgia criminal cases?
Polygraph evidence occupies a limited place in Georgia criminal cases, because the admissibility of such evidence is restricted. Understanding these limits clarifies how polygraph evidence may or may not bear on a case.
The admissibility of polygraph evidence is limited. Polygraph results are generally not admissible in the same way as other evidence, and their use is subject to significant restrictions. Whether and how such evidence may be considered is governed by these limits, which generally keep polygraph results out of evidence absent particular circumstances such as an agreement between the parties.
Stipulation can affect admissibility. In some circumstances, polygraph evidence may be treated differently where the parties have agreed to its admission, so whether there was such an agreement can be significant. Any stipulation between the parties is examined for its effect.
The reliability concerns underlie the limits. The restrictions on polygraph evidence relate to concerns about its reliability, which inform how such evidence is treated. Why the limits exist is relevant to understanding the role of polygraph evidence.
The use of polygraph evidence generally depends on the significant limits on its admissibility, the potential effect of a stipulation, and the reliability concerns underlying the restrictions. The limited admissibility, the role of any agreement, and the basis for the limits are the considerations relevant to how polygraph evidence bears on a case. The restrictions reflect longstanding doubts about reliability, which is why such results rarely carry the weight a party offering them might hope.