No one was injured in the incident, which Tabler said happened about 4:15 p.m.
The bus driver was delayed in continuing her route from T.A. Lowery Elementary School after dropping the boy off, because a train was about to cross W.Va. 230 and the crossing barriers were going down, Tabler said.
The boy was not happy when he got off the bus, where he had been "acting up" before the incident, Tabler said he determined in his investigation.
"And the driver continued to correct him in a very professional manner," Tabler said.
While waiting for the train to pass, the students on the bus noticed the boy had gotten the rifle from his home and was aiming it toward the bus, Tabler said.
After hearing them say "he's got a gun," the driver remained calm and instructed the students to get on the floor, Tabler said Wednesday.
The bus driver contacted the school district's bus garage for help and drove from the scene of the incident, Tabler said. She told officials the rifle the boy was holding appeared to be a shotgun, Tabler said.
The boy was taken into custody at the scene of the incident, which happened while his mother was home, Tabler said.
Felony offenses, such as terrorist acts, are considered Level IV violations by the West Virginia Department of Education and require the mandatory suspension of the student from school, or from transportation to or from the school on any school bus, after an informal hearing, according to the West Virginia Department of Education Student Code of Conduct.
The Jefferson County Board of Education also could consider a recommendation that the student be expelled from the school district.
Charges filed against a child younger than 14 cannot be transferred to adult status, Groh said.
Court proceedings involving a juvenile must be kept confidential in accordance with state law. Unless a juvenile requests a jury trial, the outcome of any allegations filed by police also are confidential.