Tennessee Code Title 39. Criminal Offenses § 39-17-1318

(a) If any firearm confiscated and adjudicated as contraband pursuant to this part or any other law could be sold at public auction or retained by a law enforcement agency for law enforcement as provided in § 39-17-1317, but for the fact that the serial number of the firearm has been defaced or destroyed, the commissioner of safety or the sheriff or chief of police, as appropriate, of the county in which the firearm was confiscated may send the firearm to the director of the Tennessee bureau of investigation. The director shall assign the firearm a new serial number, permanently affix the number to the firearm, record the number in the bureau's computer system, and send the firearm back to the commissioner of safety, the sheriff or chief of police for disposition in accordance with this part.

(b) If any firearm assigned a new serial number pursuant to subsection (a) is later sold at public auction, ten percent (10%) of the proceeds of the sale shall be returned to the general fund of the state to defray the costs incurred by the director in administering this section.