LANSDALE, Pa. (CBS) — Authorities say that a former instructor at North Penn High School in Montgomery County has been arrested and charged with institutional sexual assault.

Mark Miller was employed at the school to lead the ROTC unit, according to the Montgomery County District Attorney.

Authorities say on December 15, North Penn’s principal called police in connection with a reported sexual incident involving a teacher.

The principal told police he had received information from a number of individuals who said Miller had sexual relations with the student.

The student victim was reported as being a member of the ROTC unit at the school.

Officials say the victim told authorities she had sexual intercourse with Miller multiple times, including in a hotel room, where police say they were able to capture surveillance images of Miller and the victim in the lobby.

The alleged sexual relations took place between November and December 2016, police say.

According to an affidavit obtained by Eyewitness News, authorities say Miller had consensual sex with the 18-year-old student in his car and at the hotel. The affidavit also states that another student came forward and said Miller pursued her and wanted to have children with her. That student told authorities she did not have sex with Miller.

The North Penn School District says Miller resigned on December 14, 2016.

‘Mark Miller, a former military science instructor in the North Penn High School JROTC program who resigned his position, has been charged with sexual misconduct with a student. High school officials contacted Towamencin Township Police on December 14, 2016 when students reported allegations against the accused. The employee was hired in 2013 as a military science instructor for the Air Force JROTC Program at North Penn High School. He submitted his letter of resignation on December 14, 2016.

Charges such as these against Miller are contrary to the core values that educators hold true and will never be tolerated in the North Penn School District. As always, North Penn High School has the staff and resources in place for students who may need extra support during this time. Student safety is a top priority of the North Penn School District. Students are commended for reporting and acting upon this serious issue.’

Authorities say Miller is charged with institutional sexual assault, because of his position as a teacher, and criminal use of a communications facility. He was arraigned and released on $50,000 unsecured bail.

He waived his first preliminary hearing, authorities say.

Miller is retired from the United State Air Force and is certified as an ROTC teacher, the DA confirms.