KYLE, Texas — A substitute teacher has been fired and charged with aggravated assault following the beating of a 15-year-old female high school student in an incident captured on video.

Tiffani Shadell Lankford is free on $10,000 bond after her arrest Friday afternoon. If convicted of the second-degree felony, she could be sentenced to two to 20 years in prison.

Video of last week's incident in a foreign-language class at Lehman High School in Kyle, Texas, about 20 miles (32 kilometers) south of Austin went viral.

Court records list no attorney for the 32-year-old San Marcos woman, and her telephone number is not published.

The students in the class were being loud and the situation escalated when the teacher cursed at them, said Paul Batrice, an attorney for the girl's family. The girl told the teacher not to talk to her that way, he said.

One video shows the teacher striking the student several times on her head before she stomped on the girl's head. Batrice said in a statement the teen is being treated for "severe injuries."

"This is unacceptable to say the least, and we will demand justice to the fullest extend of the law to enact the change so obviously necessary," he said.

Lankford started working for the Hays Consolidated Independent School District on Aug. 30. She had worked 18 times as a substitute teacher, starting on Sept. 13 and ending Friday.

"We are appalled at the actions of this former employee. There is absolutely no excuse or circumstance that can justify what you see unfold on the video. It is unconscionable what this adult did to one of our students," said school district spokesman Tim Savoy in a statement.

The incident has caught the attention of Texas Gov. Greg Abbott, who called for an investigation of the district.

"Conduct like this won't be tolerated in Texas classrooms. The substitute teacher who committed this heinous act has been arrested and will face serious legal consequences. The school district will be investigated by the Texas Education Agency," he said in a statement.