A former California school aide has pleaded guilty to sex crimes after being accused of having a sexual relationship with a 17-year-old student, authorities said.

Lisette Veles Ortega, 32, who worked as a student support aide through an outside contractor at a secondary school in Imperial Beach, admitted to charges of unlawful sexual intercourse with a minor and oral copulation with a minor, according to the San Diego County District Attorney’s Office.

Ortega was arrested in May, when she was 31. At the time, she was employed at Mar Vista High School under contract with Ro Health, a medical staffing and home care agency that also provides nurses to schools and other institutions.

Prosecutors said her guilty plea does not include a stipulated sentence. She is scheduled to be sentenced next month at the South County courthouse in Chula Vista.

According to the San Diego County Sheriff’s Department, allegations surfaced on May 19, when deputies were called to investigate. Detectives determined there was probable cause to conclude that Ortega engaged in sexual encounters with the student off campus over the past year.

Following the case, Ro Health issued a statement saying student safety is a “top priority” and that the company maintains strict employee screening processes, including Department of Justice and FBI background checks.

Information from NBC 7 San Diego.