Airline officials told WSOC-TV that passengers with connecting flights had to go through security checkpoints again before boarding their connecting flight.
Transportation Security Administration officials said the device may have been left on the plane by a staff member or a cleaning crew. It also may have been brought through a security checkpoint in San Francisco.
They said the originating airport in San Francisco doesn’t have TSA agents, but the airport contracts with a private company. An official said that company still must abide by TSA guidelines and regulations.
FBI agents are investigating who brought the stun gun on the plane.