A person generally commits the criminal offense of sexual assault of a child—regardless of whether the person knows the age of the child at the time of the offense—if the person (1) causes the penetration of the anus or sexual organ of a child by any means; (2) causes the penetration of the mouth of a child by the sexual organ of the person; (3) causes the sexual organ of the child to contact or penetrate the mouth, anus, or sexual organ of the person or another person; (4) causes the anus of a child to contact the mouth, anus, or sexual organ of the person or another person; or (5) causes the mouth of a child to contact the anus or sexual organ of the person or another person.

The naming and definition of the criminal offense of sexual assault of a child varies from state to state. These criminal offenses are generally located in a state’s statutes—often in the penal or criminal code.

In Mississippi, the criminal offense of sexual assault of a child is addressed under the state's statutory laws, specifically within the Mississippi Code of 1972. The relevant statutes are found in Title 97, which pertains to crimes, and more specifically in Chapter 3 that deals with sex crimes. The offenses described, such as penetration or contact involving a child's sexual organs, anus, or mouth, are generally categorized under sexual battery or statutory rape, depending on the circumstances of the case. Mississippi law defines a child as a person under the age of 16 for the purposes of statutory rape (Section 97-3-65), and the age of consent is 16. It is important to note that under Mississippi law, lack of knowledge of the child's age is not a defense for statutory rape or sexual battery when the victim is under the statutory age of consent. The penalties for these offenses are severe and can include lengthy prison sentences, fines, and registration as a sex offender.