Indiana Code Title 25. Professions and Occupations § 25-37.5-1-9

Sec. 9. (a) A person may not sell or attempt to sell, and a valuable metal dealer may not purchase or attempt to purchase, a catalytic converter, in whole or in part, as valuable metal when the catalytic converter is not attached to a motor vehicle at the time of the sale or attempted sale, unless the seller is a used parts dealer or an automotive repair company.

(b) Subsection (a) does not apply when the seller presents the valuable metal dealer with an affidavit executed by a law enforcement officer attesting to the officer's reasonable belief that the catalytic converter lawfully came into the possession of the person attempting to sell the catalytic converter.