The Washington State Patrol has been called in to assist after a recent inventory check of the weapons stored in the Grant County Courthouse in Ephrata found a military-style rifle was missing.

Sheriff Tom Jones said, "I am enormously concerned about this missing rifle."

The gun had been logged into the secured firearms room at the courthouse, but it isn't there now. The sheriff's office conducted an internal investigation but the gun did not turn up. The weapon, similar to the military M-16 rifle, is used by the the Grand County Sheriff's office and numerous police forces nationwide. It fires a 7.62 millimeter round.

Officials did not say if it was one of their own, or if they took possession of this particular gun from a crime or an investigation.