Child molestation (sexual assault or abuse) is generally defined as physical contact or other interaction between a child (under age 17, for example) and an adult when the child is being used for the sexual stimulation or pleasure of the perpetrator or another person. In addition to physical contact, child molestation may include (1) the exposure of the genitals of an adult in the presence of a child, (2) the exposure of the genitals of a child, (3) using a child in making pornography, or (4) making a child view sexual acts or pornography.

Child molestation laws vary from state to state, and criminal charges for child molestation and related crimes are sometimes called (1) sexual assault of a child, (2) aggravated sexual assault of a child, (3) sexual abuse of a child, (4) indecency with a child, (5) sexual performance by a child, (6) sexual trafficking of a child, or (7) prostitution of a child.

In some states multiple instances of sexual contact between an adult and a child may constitute the enhanced criminal offense of continual sexual abuse of a child—which is sometimes a first-degree felony offense.

Child molestation laws are usually included in a state’s penal or criminal code (statutes)—which provide for the related criminal charges—and in a state’s family code (statutes) that address the civil (non-criminal) implications of child molestation—often in the context of divorce and child custody matters.

Except in limited circumstances, federal laws generally do not apply to child sexual abuse matters that take place within a single state—without transportation of the child or other materials (photographs, videos, etc.) across state lines. Such criminal matters that take place within a single state are generally handled by state or local authorities and prosecuted under state laws. But if the sexual abuse or molestation of a child involves conduct or materials in multiple states, or occurs on federal lands (military bases, American Indian territories) the offense may be prosecuted under federal law.

In Missouri, child molestation is addressed under state statutes that define various forms of sexual abuse against children. Missouri law considers a child to be anyone under the age of 17. Child molestation can include inappropriate physical contact, exposure of genitals by an adult to a child or vice versa, involving a child in the production of pornography, or forcing a child to view sexual acts or pornography. The state's criminal code outlines specific offenses such as 'child molestation' and 'statutory sodomy' with varying degrees based on the nature of the conduct and the age of the child. Charges can range from misdemeanors to felonies, with more severe penalties for aggravated or repeated offenses. Missouri law also recognizes the offense of 'child enticement' for attempting to lure a child for illicit purposes. In cases where multiple instances of sexual contact occur, the perpetrator may face enhanced charges. While most child molestation cases are handled at the state level, federal jurisdiction may apply if the offense involves crossing state lines, involves federal lands, or if there is distribution of materials such as child pornography across state lines.