WASHINGTON — A Charles County Public Schools teacher faces multiple charges and is accused of inappropriate contact with students over a seven-year period, the schools superintendent announced Wednesday.

Ralph Marvin Van Dyke Jr. was charged with sexual abuse of a minor and sexual offense in the fourth-degree stemming from students’ reports. His charges came to light after a sealed grand jury indictment was made public Wednesday during a bond hearing, Superintendent Kimberly Hill said in a message to parents and guardians.

Van Dyke, an instrumental music teacher since 2006 at North Point High School in Waldorf, Maryland, is accused of having inappropriate contact with students from 2010 to 2017, Hill said.

Van Dyke’s personnel file had contained several previous complaints, Hill said: two were reprimands for inappropriate conduct — one was from 2006 from a Thomas Stone High School principal and another was from 2012 from Hill when she was a principal at North Point — and a third complaint was from a teacher to a vice principal that was not student-related.

Hill said that when the school system was notified of the incident, it immediately removed Van Dyke from his teaching duties and ordered that he have no contact with students.

In a separate message, North Point principal Daniel Kaple told parents and guardians that Van Dyke was put on administrative leave and assigned temporarily to an administration building since Nov. 15, 2017.

“Charles County Public Schools’ general practice is to immediately remove any employee accused of inappropriate behavior from having contact with students during the investigation of charges,” Hill said in her message.

But, she added that the school system puts the employee on administrative leave with pay or assigns them to a temporary position in the administrative offices until “resolution of the charges,” which, Hill said, “allows for a thorough and unbiased investigation.”

“Resolution can take months, even more than a year, depending on how long it takes for outside agencies to investigate, file charges or adjudicate the case,” Hill said.