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 Nebraska, the criminal offense of sexual assault of a child is defined under Nebraska Revised Statute 28-319.01. The statute outlines that an individual commits first-degree sexual assault of a child if they are 19 years of age or older and they engage in any form of sexual penetration with a person under the age of 16. The law does not require the perpetrator to have knowledge of the child's age to be charged with the offense. The statute also covers various acts of sexual contact and penetration as described in the query, including causing a child to engage in or be subjected to sexual penetration or contact with any body part or object, including the sexual organ of the perpetrator or another person. This offense is a felony, and the penalties are severe, often including mandatory minimum prison sentences. Nebraska law takes these offenses very seriously, and the state's legal system is structured to protect minors from sexual abuse and exploitation.