Updated

A couple raising a 14-year-old developmentally disabled student say they hid a recording device on the girl to prove a teacher and school aide were bullying her, and a subsequent investigation has led to a lawsuit, the aide's resignation and disciplinary action for the teacher.

The girl's mother and the mother's longtime boyfriend said in court documents they complained about the mental and emotional abuse to school officials in the Miami Trace district southwest of Columbus, and then secretly recorded instructors' comments for four days last spring after their claims were rebuffed.

A $300,000 settlement was reached in a lawsuit filed this year by the girl's family against the school district, aide Kelly Chaffins and teacher Christie Wilt, attorneys said.

In the recording, voices identified as Chaffins and Wilt are heard questioning the girl's weight and how active she is and making derogatory comments about her character and the character of her mother and the boyfriend.

"Are you that damn dumb? Are you that dumb?" Chaffins said. "Oh, my God. You are such a liar. ... You told me you don't know. It's no wonder you don't have friends. No wonder nobody likes you. Because you lie, cheat ... steal."

In another instance, Wilt apparently talks to the girl about the results of a test before evaluating it. "You know what, just keep it," she said. "You failed it. I know it. I don't need your test to grade. You failed it."

The girl's mother, Kourtney Barcus, and her boyfriend, who helps raise the girl, said in the lawsuit that their concerns about the aide spanned several years before they recorded the audio and that school officials initially rejected their claims.

But they were shocked by what they heard on the hours of tape.

"We couldn't know. We didn't know," the boyfriend, Brion Longberry, said Tuesday on NBC's "Today" show.

In comments to the local newspaper, district superintendent Dan Roberts acknowledged this week that there was a problem.

"The persons involved fell short of our mission," Roberts told the Washington Court House Record Herald, which first reported the story. "We're sincerely sorry for that and we will work very hard to never let that happen again. We need to provide proper training and restate our expectations of how we treat children so that this never happens again."

In an email to a social worker in April, Roberts said he had looked into similar complaints from the boyfriend earlier in the year and found that the girl was lying. "It came to a point where I had to remind the man that his continued false accusations were bordering on harassment and slander," the email says.

The lawsuit alleged verbal and emotional abuse and inappropriate comments by the aide and the teacher, as well as failure by school officials to report suspected child abuse. It also said the instructors put the girl on a treadmill if they were not satisfied with her work.

The school has said the treadmill is used strategically to help students focus.

Chaffins resigned, and the State Board of Education on Tuesday accepted her decision to give up her educational aide permit "based upon her inappropriate comments to students," according to board documents.

That prohibits Chaffins from getting another job as an Ohio teacher's aide.

After a confidential investigation, the board decided to suspend Wilt's license as an intervention specialist for one year because of "conduct unbecoming to the teaching profession." Under an agreement with the board,

Wilt can avoid that suspension if she remains in good standing with the district and completes eight hours of training focused on bullying awareness and reporting child abuse.

Messages left Tuesday for Roberts, Chaffins, Wilt and their attorneys weren't returned.

The Fayette County prosecutor's office reviewed the case but didn't pursue criminal charges.