NASHVILLE, Tenn. (CBS NEWS)  -- The wife of a former Tennessee schoolteacher accused of kidnapping a 15-year-old student is pleading for her husband to bring the girl home. 

District Attorney Brent Cooper has issued an additional arrest warrant for a charge of aggravated kidnapping. The teenager went missing Monday from Columbia and is believed to be with 50-year-old Tad Cummins, CBS affiliate WTVF reports.

The Tennessee Bureau of Investigation said it remains “extremely concerned” about the well-being of the 15-year-old. Tad Cummins was placed on the TBI’s Top 10 Most Wanted List. 

A statewide Amber Alert from the TBI says Cummins “may have been abusing his role as a teacher to groom this vulnerable young girl for some time in an effort to lure and potentially sexually exploit her.” 

Cummins’ wife, Jill Cummins, on Friday asked her husband to turn himself in and bring the teenager home. 

“I had no idea my husband was involved in anything that would have led to something like this...I want her home just as much as the rest of you,” Jill said as her family pastor stood beside her, WTVF reports. 

She went on to speak to Tad saying, “this is not who you are.” 

TBI’s Josh Devine tsaid that they have received a “shockingly low number of tips” in the alert, leading them to believe the pair is either out of the view of the public or are outside of the original net of search, WTVF reports. 

“This is a dire situation for this young girl,” Devine said.

District Attorney Cooper said the teen has not tried to contact any of her family since Monday when she went missing.

Tad Cummins formerly taught at the Culleoka Unit School. He was fired after the alert was issued.  

The teen is one of ten children, and her mother is facing five counts of child abuse, WTVF reports. Investigators believe she was carefully groomed and then brainwashed by Cummins into abandoning her family to be with him.