Robin Davenport ties up crime-scene tape at the scene of a 2008 shooting on Ryan Street in Chattanooga.

A Chattanooga police officer will not face criminal charges after he exchanged about 1,700 text messages and phone calls with an 11-year-old girl during a two-week span in late 2015, records show.

Hamilton County District Attorney General Neal Pinkston reviewed the Tennessee Bureau of Investigation's probe into Officer Robin Davenport earlier this year and decided not to charge the man because of a "lack of evidence," police internal affairs records show.

Davenport was accused of inappropriately texting the girl and was investigated by TBI for sexual exploitation of a minor, a felony. The police department's internal affairs investigation into Davenport is still ongoing, and he could still be disciplined or fired. He has been on paid administrative leave since the investigation began in October.

In the text messages, Davenport and the girl talk about everything from baking cookies to how a man's sperm fertilizes a woman's egg. They refer to each other by nicknames like "stinky butt," "green butt" and "saggy boobs." Davenport jokes with the girl, offers advice and asks for photos of her, which she sends.

Davenport told internal affairs investigators his relationship with the girl was as a father to a daughter. But the girl's mother said the text messages seemed sexually suggestive and inappropriate.

The girl will not be identified in the Times Free Press because she is a minor, and the mother will not be named to protect the identity of the girl.

The girl's mother had dated Davenport, and she told the Times Free Press in a November 2015 interview that she considered him a family friend. A single parent, the woman said she invited Davenport to mentor her daughter as the girl transitioned into middle school. But she reported Davenport to internal affairs when she reviewed the conversations on her daughter's phone in October.

Davenport sent the girl 955 text messages and received 763 messages from the girl between June and October 2015, according to the police internal affairs report. She sent him 47 pictures, and he sent her eight photos.

The two interacted 1,791 times during that four-month span, phone records show. But the vast majority of those texts and phone calls — about 1,776 — were exchanged in the 14-day stretch between Sept. 22 and Oct. 5, 2015.

During an about 90-minute interview with internal affairs investigators in February, Davenport said he felt the volume of texts between them was normal, that he was never alone with the girl, and that the girl's mother was twisting an innocent relationship. He said many of the texts and nicknames were jokes and good-natured ribbing.

"The saggy boob joke," he said. "I had on a tank top that day, I was working out. [The girl] looked at me and pointed and she said, 'Oh look, mom, he's got saggy boobs.' It's a joke. It's like, it's hard to sit here and answer this. I know it was funny. It's funny. It was a lot of fun. It was hilarious to me. But where it hurts at is that [the mother] would take that after being involved in it and knowing it, and try to turn it into something else that it's not."

Davenport could not be reached for comment on this story, and the girl's mother did not return a recent request for comment. In November, she said she wanted to see Davenport fired. He has been an officer with Chattanooga since 2001 and works in the fugitive division.

The text conversations happened at all hours of the day and into the night. The longest break between texts is eight hours, according to the internal affairs report. At one point, Davenport and the girl discuss "how eggs turn into babies," and he explains the process in scientific terms. He asks why she is so interested in the topic, and she says she was learning about it in school.

At another point, the girl gets in trouble at school and Davenport tells her how he was kicked out as a teenager because he brought a gun to school. He said he then earned his GED and graduated from college, and urged her to be careful who she hangs out with.

"Choosing the right friends is an important thing," he wrote. "All that seems cool might not be cool at all. If your friends are doing foul things or trying to get you to do foul things then the truth is that they may not be your friend at all."

Davenport and the girl also regularly exchanged photos in the messages and often talked about showering and bathing.

"My mom said bed time," the girl wrote.

"Did you shower," Davenport replied.

"O no I didn't have to take one," she wrote.

"Yucky," he said.

Three times, Davenport sends the girl a photo of himself where he is shirtless and flexing at the camera. After he sent the photo to the girl the first time, he then asked, "Where's my picture like that." When he sent it for the third time, three days later, he wrote, "Are your muscles bigger than mine?"

Davenport told internal affairs investigators he sent the photo as part of a "muscle competition" between him and the girl. He said the girl's mother gave him permission to send the photo. The girl later sends him a photo of herself, fully clothed and also flexing at the camera. Davenport said the mother took that photo of her daughter.

After the girl received the first shirtless photo from Davenport, she asked him if she could make a copy of it. He asks why and tells her she can't show the picture to anyone because he is shirtless.

"Would you want me looking at a picture of you with your shirt off?" he wrote.

"Idc I don't have boobs dey small," she replied.

"Lol silly," Davenport wrote back.

"I told my friends tho was dat ok?" she wrote.

"Well I'm going to copy your shirtless picture and hang it on my wall when you send it lol," Davenport wrote. Then, "You told your friends what?"

"Dats ok cuz I dnt have big boobs," the girl replied. "Brb my teacher is here now."

When internal affairs investigators asked about that exchange, Davenport said he was trying to make a point to the girl that it was inappropriate for her to show anyone his shirtless photo.

Contact staff writer Shelly Bradbury at 423-757-6525 or with tips or story ideas. Follow @ShellyBradbury.