How Georgia Deputy's Anonymous Good Deed Came Back to His Sheriff's Office When the woman ran out to thank him, the officer was already driving away.

 -- A Georgia sheriff's deputy was off-duty when he saw a struggling pregnant woman at a gas station, and he anonymously stepped in to help.

The woman was in line Thursday, June 18 at a gas station in Forsyth County, Georgia, about 40 miles north of Atlanta.

She was on the phone with her fiance, telling him how she was trying to scrounge up enough money to put $10 of gas in her tank, according to Forsyth County Sheriff's Office spokesman Robin Regan.

"It was the day before pay day," Regan told ABC News. "She was just trying to make it to the end of the week."

A Forsyth County Sheriff's deputy was in line in front of her and overheard her phone call. He was still in uniform, Regan said, but his shift was done for the day, and he was about to drive home.

The deputy quietly paid for her gas, later telling Regan it "seemed like she needed help."

"He managed to sneak out before she realized what had happened," Regan said.

Once the woman got off the phone and went to pay for her gas, the clerk told her the deputy already took care of it, Regan recounted. The woman then ran out the door to try to thank him, but saw the officer driving away.

She sent a Facebook message to the sheriff's office, describing the deputy and his car.

"We knew exactly who he was," Regan said. The deputy tried to stay anonymous, "But we quickly realized that he was the one who had done it."

Regan said the deputy later told him it "seemed like the right thing to do."

The anonymous officer has been a deputy for about 12 or 13 years, Regan said.

"I've worked with the guy for a long time and he's a very good guy. Definitely somebody I'm very proud to work with," Regan said.

"We're very proud of our deputies here," Regan added. "This is what their character is all about. They do things like this every day."

The woman, identified by ABC affiliate WSB-TV as Alex Davis, did not immediately respond to ABC News' request for comment, but Davis told WSB the officer's act of kindness "blew me away."

"It was so classy and humble," Davis said.

"I'm just this average girl who is pregnant and trying to get on her feet," she told WSB. "It was incredible."