WALTON COUNTY, Ga. -- A volunteer firefighter for the city of Oxford has been charged with child exploitation.

Authorities said Lewis McClain, 24, was messaging someone over the Internet he thought was a 12-year-old girl. He also called her and emailed pictures to her, according to officials.

Police said the person he was chatting with was actually a detective.

Authorities arrested McClain Thursday night while he was teaching a firefighting class.