[UPDATE] According to court documents, the boy was planning to shoot up the school for political reasons.

[He] stated that he wanted to prove to people that you don't need an assault rifle to shoot up a school," the court documents say. "[He] was going to show people that it could be done with a couple of handguns."

[via nbcmontana.com]

BUTTE, Mont. (AP) — A 14-year-old boy charged with bringing two guns to Harrison Public Schools, including a loaded .357 Magnum, is being held at a juvenile detention facility in Galen.

The Associated Press reports the boy had a detention hearing Monday in Virginia City before Youth Court Judge Loren Tucker. The judge entered a plea of "not true" to a criminal endangerment charge.

The boy was arrested Friday after school officials found two guns in his backpack on school property. Another student tipped school officials.

The boy is being held at the Reintegrating Youthful Offender Correctional Facility, which is a secure facility where he also will attend school. A status hearing is set for Feb. 25.