A person generally commits the criminal offense of public lewdness or lewd conduct in public if the person knowingly engages in any of the following acts in a public place—or, if not in a public place, the person is reckless about whether another is present who will be offended or alarmed by the person’s (1) act of sexual intercourse; (2) act of deviate sexual intercourse; (3) act of sexual contact with a person’s own private parts or those of another.

Public lewdness laws vary from state to state, and some states define and charge such criminal offenses under indecent exposure laws. Public lewdness is usually a misdemeanor offense, but may be a felony offense under some circumstances. And in some states a conviction for public lewdness may require the defendant to register as a sex offender.

In Illinois, the criminal offense of public lewdness is typically addressed under the state's indecent exposure laws. According to Illinois Compiled Statutes, specifically 720 ILCS 5/11-30, a person commits public indecency when they perform an act of sexual penetration or sexual conduct, or a lewd exposure of the body with the intent to arouse or satisfy the sexual desire of the person, in a public place or in a place where the conduct may be viewed by others. Public indecency is classified as a Class A misdemeanor. However, if the individual has a prior conviction for this offense, subsequent offenses may be elevated to a Class 4 felony. It's important to note that certain acts of public lewdness, especially those involving minors or that are particularly egregious, may result in more severe charges and penalties, including the possibility of having to register as a sex offender under the Illinois Sex Offender Registration Act (730 ILCS 150/1 et seq.). The specifics of each case can greatly affect the charges and potential penalties, so it is advisable for individuals facing such charges to consult with an attorney for legal guidance tailored to their situation.