Police say the gun is an heirloom. It was not loaded, and the boy didn't threaten anyone.
Police say the weapon is a rusty .357 magnum revolver that the boy's family considers an heirloom.
Officials say charges haven't been filed. Police Cmdr. Lou Jogmen says authorities will work with the boy in an informal setting.
Gunderson says students have since been instructed about what to do in similar situations.
The Associated Press contributed to this report.
