AUSTIN, Texas – The LBJ High School teaching assistant accused of having an improper relationship with a student has been arrested.

Stephone Mercer, 27, is facing a second degree felony for allegedly having sexual contact with a student, according to the arrest affidavit.

Police were first notified of the incident on Oct. 12, when a friend of the victim told another teaching assistant at the Austin ISD school about what happened.

After obtaining a search warrant for the cell phones of Mercer and the student, police were able to confirm that an improper relationship had occurred.

During a police interview, Mercer admitted to engaging in a one-time sexual act with the student. The victim told police she initially thought Mercer was a student who had recently graduated and did not know he worked for the school.

Mercer was fired from LBJ High School on Oct. 30. School officials will continue to invesigate the incident. 

"As always, we appreciate your support as we work together to ensure each student’s safety at LASA and LBJ ECHS," said LBJ High School Principal Sheila Henry. 

AISD has reported the incident to the Texas Education Agency.