Thirty-year-old Tara Grinstead is a teacher and a doctoral student at Valdosta State University.
Grinstead's sister says police are questioning her ex-boyfriend.
Anita Gattis, Tara Grinstead's sister, says, "They broke up approximately nine months ago. He has been questioned many times at length, he has obtained an attorney. They had had a very bad argument. I just found out several days before she went missing concerning an 18-year-old he was dating."
The missing woman's sister also says police have questioned a man obsessed with Grinstead.
There's an $80,000 reward for information leading to her safe return.