The U.S. Department of Education has opened a Title IX investigation into Fairfax County Public Schools over reports of an adult illegal immigrant student sexually assaulting female students.

The department told WTOP that it will review whether the school district discriminated on the basis of sex in its response to the sexual assault accusations from a dozen female students.

“Fairfax County Public Schools (FCPS) received the complaint yesterday and is reviewing it. We are prepared to fully cooperate with the U.S. Department of Education’s inquiry,” FCPS told the news outlet on Tuesday.

Israel Christopher Flores-Ortiz is an illegal immigrant from El Salvador who is almost 19 years old and in 11th grade at Fairfax High School, and has been charged with multiple counts of assault and battery after several female students told police he touched them inappropriately in school hallways. He was arrested last month and remains in jail without bond.

The Department of Homeland Security asked the county to turn Flores-Ortiz over to U.S. Immigration and Customs Enforcement.

FCPS said that it is working with the police investigation.

“To maintain the integrity of the ongoing investigation, we cannot share additional details at this point,” FCPS said.

FCPS superintendent Michelle Reid said last week that the school system hired an outside law firm to conduct an independent review of the case and determine whether school policies were followed.

“The goal is clear: to establish a definitive understanding of what occurred, when it occurred, and confirm that all policies, procedures, and regulations were properly followed. The firm of McGuireWoods will conduct this thorough, objective, and independent review,” FCPS said.

The Education Department said its probe into FCPS is part of a broader review of compliance with federal law involving several Northern Virginia school systems, including policies around bathroom use based on which gender students identify with.

Flores-Ortiz is scheduled to appear in Fairfax County Juvenile and Domestic Relations Court for an adjudicatory hearing on April 9.