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 Utah, incest is defined as sexual intercourse between certain close relatives, and it is considered a third-degree felony under Utah Code § 76-7-102. The law prohibits sexual relations or marriage between ancestors and descendants, including those by adoption; between siblings, whether by the whole or half-blood or by adoption; and between uncles, aunts, nieces, or nephews if they are related by the whole blood. Consent is not a defense to the charge of incest in Utah, meaning that the crime can be prosecuted even if both parties consented to the sexual relationship. Conviction of incest in Utah can result in imprisonment and significant legal penalties. It is important for individuals in Utah to be aware of these regulations to avoid legal repercussions related to prohibited sexual conduct.