A former William Penn Charter School summer camp counselor and tennis coach has been charged with sexual offenses involving a teenage counselor in the school’s 2018 summer camp program, authorities said Friday.

Christopher Spencer, 35, of the 6300 block of Overbrook Ave. in Overbrook, was arrested by Philadelphia Police on Thursday, police and the school said. He was charged Friday with attempt to commit involuntary deviate sexual intercourse, unlawful contact with a minor, aggravated indecent assault, institutional sexual assault, and related offenses.

Penn Charter, one of the city’s most prominent private schools, is the fifth-oldest school in the United States and the oldest Quaker school in the world, according to its website. Located at 3000 West School House Lane in East Falls, it has 960 students from prekindergarten to 12th grade.

Spencer’s arrest came after concerns in July 2019 when parents of another teen summer counselor reported to the school that Spencer “engaged in inappropriate online and verbal communication and interacted with their child in a way that made the child feel uncomfortable,” the school said in a statement.

In response to that report, the school “acted quickly and decisively to remove Spencer from campus and bar him from returning,” the statement said. The same day, Penn Charter reported the conduct to ChildLine, Pennsylvania’s child abuse reporting hotline, and the Philadelphia Police Department’s Special Victims Unit conducted an investigation, which was closed without further action, the statement said.

Afterward, the school said it continued an internal review following the July 2019 report and reached out to other people Spencer had been in contact with through his role at the school.

In September, the statement said, the school learned of “information that led us to believe that Spencer engaged in inappropriate sexual contact with a high school-age counselor the year before, in the summer of 2018. We immediately reported the conduct to ChildLine and, as before, worked collaboratively with the Philadelphia Police Department’s Special Victims Unit.”

“Penn Charter prioritizes the safety and welfare of the children who attend our school and participate in our programs. We are thankful to the two counselors and their families for alerting the school and are moved by the bravery they have shown in stepping forward,” the statement said.

It was not immediately known if Spencer has an attorney.