Tennessee Code Title 39. Criminal Offenses § 39-11-502

(a) Except in prosecutions for violations of §§ 39-13-504(a)(4) and 39-13-522, ignorance or mistake of fact is a defense to prosecution if the ignorance or mistake negates the culpable mental state of the charged offense.

(b) Although a person's ignorance or mistake of fact may constitute a defense to the offense charged, the person may be convicted of the offense for which the person would be guilty if the fact were as the person believed.

(c) It is not a defense to prosecution for a violation of § 39-13-309, § 39-13-514, or § 39-13-529(a), (b)(1), or (b)(2) that the person charged was ignorant or mistaken as to the age of a minor.