On Thursday, deputies from the Barstow Sheriff's Station received a report of a suspected relationship between teacher Katherine Oneill and a 16-year-old student at the school.
During the course of the investigation, investigators say they found Oneill had an inappropriate sexual relationship with the student and that the two exchanged explicit text messages.
The 51-year-old was taken into custody Friday and is now free on $100,000 bail.
Officials say Oneill has been on administrative leave since October of last year, though they won't say why.
The Crimes Against Children Detail interviewed the victim regarding the allegation of sexual abuse.
Police are asking other potential victims to come forward. Callers wishing to remain anonymous are urged to call the We-Tip Hotline at 1-800-78-CRIME (27463).