Ohio Revised Code Title XXIX. Crimes Procedure § 2923.23

(A) No person who acquires, possesses, or carries a firearm or dangerous ordnance in violation of section 2923.13 or 2923.17 of the Revised Code shall be prosecuted for such violation, if he reports his possession of firearms or dangerous ordnance to any law enforcement authority, describes the firearms of  1 dangerous ordnance in his possession and where they may be found, and voluntarily surrenders the firearms or dangerous ordnance to the law enforcement authority. A surrender is not voluntary if it occurs when the person is taken into custody or during a pursuit or attempt to take the person into custody, under circumstances indicating that the surrender is made under threat of force.

(B) No person in violation of section 2923.13 of the Revised Code solely by reason of his being under indictment shall be prosecuted for such violation if, within ten days after service of the indictment, he voluntarily surrenders the firearms and dangerous ordnance in his possession to any law enforcement authority pursuant to division (A) of this section, for safekeeping pending disposition of the indictment or of an application for relief under section 2923.14 of the Revised Code.

(C) Evidence obtained from or by reason of an application or proceeding under section 2923.14 of the Revised Code for relief from disability, shall not be used in a prosecution of the applicant for any violation of section 2923.13 of the Revised Code.

(D) Evidence obtained from or by reason of an application under section 2923.18 of the Revised Code for a permit to possess dangerous ordnance, shall not be used in a prosecution of the applicant for any violation of section 2923.13 or 2923.17 of the Revised Code.