“Reach out to someone you know and trust,” he said. “And if you don’t feel like there's anyone that meets that description, just call me. Let’s just talk about this, Julia, and let’s get you home. Let’s make sure you’re safe, and we'll take excellent care of you.”

Every indication is Mann left her home alone and of her own accord the night of Feb. 20, according to authorities. She was last seen by her grandfather as he was getting ready for bed, Berry told Channel 2 Action News.

Deputies responding the next morning to the home in the Rowan Oak subdivision off Rocky Branch Drive found a muddy footprint near a back gate. Mann’s cellphone, computer and a few of her belongings were gone, Berry said.

In the weeks since, he said he would have expected to get an electronic hit on Mann’s activity. So far, investigators have found no trace of her.

Investigators have issued five search warrants and two subpoenas, Channel 2 reported. They have searched with cadaver dogs and by helicopter, and as of this week GBI agents are pitching in, too.

“It's like she walked out the back door, she walked out the back gate and an alien craft picked her up and took her to Mars,” Berry said in an interview with the news station.

Her mother, Terrie Clark, told Channel 2 they are worried she trusted the wrong person and could be in danger. The family had just relocated to the area a few weeks before Mann went missing.

"I don't know how to live, not knowing if she's OK," Clark said. "I just have to get her home."

Mann is described as 5 feet, 3 inches tall and about 100 pounds. She has multiple piercings on her left ear.

Anyone with information on her whereabouts is asked to contact the sheriff’s office at 706-769-3945 or Investigator Golden Sanders at gsanders@oconeesheriff.org.

— Please return to AJC.com for updates.