(a) Every person confined in a penal institution or confined in any other facility under the jurisdiction of or subject to the authority of the board or who, while being conveyed to or from any facility, or while at any other location under such jurisdiction or authority, or while being conveyed to or from any such place, or while under the custody of officials, officers, or employees subject to such jurisdiction or authority, who, without authorization of the appropriate authorities, possesses or carries upon his person or has under his custody or control any instrument or weapon of the kind commonly known as a blackjack, slingshot, billy, sandclub, sandbag, or metal knuckles; or any pistol, revolver, or other firearm; or any explosive substance; or any dirk, dagger, switchblade, gravity knife, razor, or any other sharp instrument which is capable of such use as may endanger the safety or security of any of the facilities described in this subsection or of any person therein shall be guilty of a felony and, upon conviction thereof, shall be punished by imprisonment for a term of not less than one nor more than five years.

(b) A person is deemed "confined in a penal institution" if he is confined in any of the penal institutions specified in subsection (a) of this Code section by order made pursuant to law, regardless of the purpose of the confinement and regardless of the validity of the order directing the confinement, until a judgment of a competent court setting aside the order becomes final so as to entitle the person to his immediate release.

(c) A person is deemed "confined in" a penal institution even if, at the time of the offense, he is temporarily outside its walls or bounds for the purpose of confinement in a local place of confinement pending trial or for any other purpose for which an inmate may be allowed temporarily outside the walls or bounds of a penal institution; but an inmate who has been released on parole is not deemed "confined in" a penal institution for purposes of this Code section.