A substitute teacher was charged Thursday for allegedly having a sexual relationship with an Elizabeth student.

Officials say that Nataly Lopez, 27, had sex with the student inside her vehicle in Elizabeth on at least two occasions and also exchanged sexually explicit messages with him over the course of several weeks.

Lopez is not an employee of Elizabeth Public Schools, but works for Source4Teachers, a vendor that provides substitute teachers to the district, according to police. Lopez was working for School No. 3 when the incidents occurred, according to the Union County prosecutor.

“The safety of our children is always the Elizabeth Schools’ top priority,” Superintendent Olga Hugelmeyer said in a statement. “Immediately upon receiving information of inappropriate behavior by a substitute teacher…the substitute was barred from entering any school. Law enforcement and social service agencies were notified as was the substitute's employer.”

Police say that Lopez was arrested at her home Thursday without incident. She was charged with first-degree aggravated sexual assault, second-degree sexual assault, and third-degree endangering the welfare of a child.