Bethany Markowski, whose father reported her missing from a Jackson, Tenn., shopping mall, would now be 31
Bethany Markowski at age 11 in 2001, when she disappeared
| Credit: NCMEC

The mystery of Bethany Markowski's whereabouts has endured for 20 years.

It starts with the day she was reported missing on March 4, 2001. Her father — separated from Bethany's mother, Jonnie Carter, during a contentious divorce proceeding — told authorities he'd watched the 11-year-old go into Old Hickory Mall in Jackson, Tenn., while he stayed in a car and napped. When she hadn't returned after about two hours, he said he went looking for her, and couldn't find her.

But authorities turned up no proof that Bethany entered, exited or was seen inside the mall, Cathy Ferguson, a special agent with the Tennessee Bureau of Investigation, tells PEOPLE. Instead they believe she was last seen with her father the day before on a visit to friends of his in Little Rock, Ark., more than 200 miles away.

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The father "is not a named suspect," says Ferguson. But "he's not been very cooperative, and he has not participated in the investigation at all."

Bethany's mother, meanwhile, has worked with lawmakers to establish a Tennessee Missing Children's Day. It's an outgrowth of the annual vigils she held on the date her daughter disappeared, and taps into her volunteer work with the National Center for Missing & Exploited Children to highlight the plight of other families searching for loved ones.

"It feels like it was yesterday, and it feels like she was never really here," Carter tells PEOPLE. "It's kind of hard to explain. She's been gone way longer than I had her."

"The pain and the hurt and the memories ... that's a tough one on parents and siblings and family members," she says. "Not only do you lose the person — after a while you start losing the memory of them. How they look. How they smell. ... That's hard. It's really hard."

bethany markowski age progression
Credit: NCMEC

Bethany now would be 31. Multiple reported sightings in the first months after she disappeared included a claim that a woman tried to enroll a child matching Bethany's description in a school, claiming the child's father had custody. But the woman and child never returned to the school, Ferguson confirms.

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"Somebody out there knows where Bethany is and what happened to her," Ferguson says. "I really think that the Lord will move somebody's heart that knows what happened to Bethany, and they will tell us. None of us will ever stop believing that we can find Bethany."

Certainly not Bethany's mother.

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"I guess the thing that keeps me going is the fact that I'm her mom," says Carter. "If I stop, everybody stops. Not looking for Bethany is just not an option."

She continues: "She always had a smile on her face. She has the biggest heart. She couldn't stand for people to make fun of old people or kids with disabilities or kids that were poor. She didn't like it at all. She always stood up for the underdog."

"At this point, it's 20 years," adds Carter. "I could care less if anybody spends a second in jail or prison or whatever. I just want to bring Bethany home."

Anyone with information about Bethany is asked to call the Tennessee Bureau of Investigation at 800-824-3463 or email