Incest is marriage or sexual relations between close relatives. The criminal offense of incest may also be known as prohibited sexual conduct. Laws vary from state to state, but incest laws generally prohibit marriage or sexual relations between (1) a person’s ancestor or descendant by blood or adoption; (2) a person’s current or former stepchild or stepparent; (3) a person’s parent’s brother or sister of the whole or half blood; (4) a person’s brother or sister of the whole or half blood or by adoption; (5) the children of a person’s brother or sister of the whole or half blood, or by adoption; or (6) the son or daughter of a person’s aunt or uncle of the whole or half blood or by adoption.

Lack of consent to sexual relations between such relatives is not an element of the crime, and persons may be guilty of the crime even if both parties consented.

Laws regarding incest or prohibited sexual contact vary from state to state and are generally located in a state’s statutes—often in the penal or criminal code. The crime is a felony offense in many states, with potential punishment of significant jail or prison time.

In Arizona, incest is defined under Arizona Revised Statutes §13-3608 as marriage or sexual intercourse with a person whom one knows to be related to oneself, either legitimately or illegitimately, as an ancestor, descendant, or a brother or sister of either the whole or the half blood. This includes relationships of parent and child, siblings, uncle and niece, aunt and nephew, and first cousins. Incest is classified as a Class 3 felony in Arizona. The law does not require lack of consent as an element of the crime; therefore, incestuous acts are punishable even if they are consensual between the parties involved. Conviction of incest in Arizona can result in significant penalties, including imprisonment and fines.