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 Iowa, the criminal offense of sexual assault of a child is addressed under the state's sexual abuse laws, which can be found in Chapter 709 of the Iowa Code. The acts described, involving various forms of sexual contact and penetration with a child, would typically fall under the category of 'Sexual Abuse in the First Degree' when the victim is under the age of 12. Iowa law defines a child as anyone under the age of 18, but the severity of the offense and the associated penalties can vary depending on the age of the child and the age difference between the child and the perpetrator. Lack of knowledge of the child's age is not a defense to prosecution for these offenses. Sexual abuse in the first degree is considered a Class 'A' felony in Iowa, which is the most serious class of felony and can result in a sentence of life imprisonment without the possibility of parole.