Georgia Code Title 17. Criminal Procedure § 17-16-10

The defendant need not include in materials and information furnished to the prosecuting attorney under this article any material or information which the prosecuting attorney has already furnished to the defendant under this article. The prosecuting attorney need not include in materials and information furnished to the defendant under this article any material or information which that defendant has already furnished to the prosecuting attorney under this article. Either party may call as a witness any person listed on either the prosecuting attorney's or defendant's witness list.