SDCL § 22-22A-3: Aggravated incest--Related child--Felony.

Any person who knowingly engages in an act of sexual penetration with a person who is less than eighteen years of age and is either:

(1) The child of the perpetrator or the child of a spouse or former spouse of the perpetrator; or

(2) Related to the perpetrator within degrees of consanguinity within which marriages are, by the laws of this state, declared void pursuant to § 25-1-6;

is guilty of aggravated incest. Aggravated incest is a Class 3 felony.