A Charleston County School of the Arts theater manager is accused of having sex with a high school student inside the school’s theater, according to police.

Carl Barnwell Jr., 30, of Woodmere Drive in Charleston, is charged with sexual battery of a 16-year-old student, who will remain unidentified. Barnwell appeared before a bond court judge Friday morning.

The girl’s parents addressed the judge during the hearing about their disappointment with the school. “We’re sorry the school system let this happen on the premises,” the girl’s father said in court. “The school system has to change. Someone has to be smart enough to change this. We have to protect our kids.”

Charleston County School District General Counsel John Emerson released a statement on Friday afternoon: “We did a criminal background check on him as we do every new hire. Neither Mr. Barnwell’s history, nor his performance as an employee with the district, suggested in any way that he might engage in the conduct of which he is accused. Once the allegations were made, we immediately placed Mr. Barnwell on administrative leave pending an investigation. At this time, it is a police matter and additional questions about the investigation should be directed to the City of North Charleston Police Department.”

The student’s parents did not want to comment further following the hearing. A judge set Barnwell’s bail at $50,000. Barnwell is accused of having sexual intercourse with the student on the school’s property between March 1 and May 30, according to an affidavit.

The student told police that she has had sex with Barnwell about once a week since December 2012, according to the court document. She also told investigators she had sex with Barnwell on two separate occasions at the school’s “upstairs area of the theatre,” the affidavit stated.

Police have video of Barnwell admitting to them that he had sex with the student on school grounds, according to the affidavit.

His attorney, David Aylor, who appeared before the judge, said that Barnwell graduated from the College of Charleston with a theater degree and has no prior criminal record.

This was Barnwell’s second year working as a theater manager for the School of the Arts, Aylor said. Barnwell went to high school in Beaufort and has worked in several theater houses outside of the area, according to Aylor.

The school’s principal reported to police that a parent had told her that she had “compelling evidence of a teacher having a inappropriate relationship with student,” a police report stated.

Police interviewed that parent, who told investigators she had letters between her daughter and the alleged victim talking about an affair between a student and teacher, the report stated.

The letters were later obtained by police. The alleged victim also identified Barnwell as her mentor and “tech teacher.”

“I trusted this man. He looked me in the face and lied to me. I don’t have faith in anything anymore,” the student’s father told the judge.

Reach Natalie Caula at 937-5594 or Twitter.com/ncaula.