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 New Mexico, the criminal offense of sexual assault of a child is referred to as 'criminal sexual penetration' or 'criminal sexual contact of a minor' depending on the nature of the act. Under New Mexico law, criminal sexual penetration includes any of the acts described where there is any coerced or non-consensual penetration, regardless of the orifice. Criminal sexual contact of a minor includes any unlawful and intentional touching of a child's intimate parts, or the unlawful and intentional causing of a child to touch the offender's intimate parts. New Mexico law does not allow for the defense that the perpetrator did not know the age of the child at the time of the offense. These crimes are felonies, and the severity of the charges can vary based on factors such as the age of the child and the use of force or coercion. The specific statutes detailing these offenses can be found in the New Mexico Statutes Annotated (NMSA), particularly in Chapter 30, Article 9, which covers criminal sexual offenses.