School officials said the man got in the school Wednesday by walking through the front door as a vendor left the building.
Police said the man took two laptop computers and two cameras before fondling the girl. A school official told the Akron Beacon Journal the front door can only be opened by a buzzer or from within.
He said staff members and students know not to let anyone inside and that school officials will make sure all visitors will be told that, too.
Police said the 21-year-old Barberton man was charged with breaking and entering, criminal trespassing and gross sexual imposition.