Title 24, Chapter 9, Section 5
(a) Except as provided in subsection (b) of this Code section,
persons who do not have the use of reason, such as idiots, lunatics
during lunacy, and children who do not understand the nature of an
oath, shall be incompetent witnesses.
(b) Notwithstanding the provisions of subsection (a) of this Code section, in all cases involving deprivation as defined by Code Section 15-11-2, or in criminal cases involving child molestation, and in all other criminal cases in which a child was a victim of or a witness to any crime, any such child shall be competent to testify, and his credibility shall be determined as provided in Article 4 of this chapter.