KATY, Texas (CBSDFW.COM) – A teacher’s aide at a Houston-area high school is being accused of slapping and throwing a cellphone at a student with autism during an altercation last month, according to court documents.

Crystal Sedlar has been charged with felony injury to a child or disabled individual.

According to court documents obtained by KTRK, the 15-year-old student at James E. Taylor High School in Katy ISD was being argumentative and a special education teacher was addressing the student when Sedlar became involved. Sedlar then allegedly put herself in between the two and grabbed the student’s arm to move him away.

This led to an altercation between Sedlar and the student, according to court documents. The teenager allegedly pulled Sedlar’s hair and slapped her, which led to her slapping him back. As the fight was being broken up, Sedlar allegedly threw her cellphone at the student as he was walking away, which hit him in the back of his head.

Katy ISD said Sedlar resigned from her position as the district was investigating the incident. The district told KTRK in part: “The Katy ISD Police and Human Resources Department recently investigated an allegation involving a paraprofessional… the investigation led to a Third-Degree Felony- Injury to a Child or Disabled Individual charge being recommended to, and accepted by, the District Attorney.”

A psychotherapist talked to KTRK about the incident and said a teacher’s aide should not be touching a child.

“It’s elevated because it’s a special needs child,” Micki Grimland said. “… But for a person to be so reactive and impulsive in their reactivity in a harmful way to a child has no business being anywhere near a child just by virtue of they’re the adult and the child is the child.”