Ga. Code § 20-5-55
An agent or employee of a public library or of any department or office of the state or local government causing the arrest of any person pursuant to the provisions of this part shall not be held civilly liable for unlawful detention, slander, malicious prosecution, false imprisonment, false arrest, or assault and battery of the person so arrested unless excessive or unreasonable force is used, whether such arrest takes place on the premises by such agent or employee; provided, however, that, in causing the arrest of such person, the public library or agent or employee of the public library had at the time of such arrest probable cause to believe that the person committed willful theft or concealment of books or other library property.
OCGA § 20-5-55