N.H. Rev. Stat. Ann. § 262:7

Any person who buys, receives, possesses, sells or disposes of a motor vehicle or an engine for a motor vehicle, knowing that a vehicle identification number of said motor vehicle or engine has been removed, defaced, obliterated, or changed shall be guilty of a misdemeanor; provided, however, if upon discovery by any person that a vehicle identification number has been removed, defaced, obliterated, or changed, he shall report the same to the nearest police station and shall not be charged with a violation of this section.