S.D. Codified Laws § 22-23-1.2

It is an affirmative defense to a charge of prostitution under § 22-23-1 if the defendant proves by a preponderance of the evidence that the defendant is a victim of human trafficking under chapter 22-49 or that the defendant committed the act only under compulsion by another person who, by implicit or explicit threat, created a reasonable apprehension in the mind of the defendant that if the defendant did not commit the act, the person would inflict bodily harm upon the defendant.