A person commits the offense of criminal trespass or criminal trespassing by entering or remaining on the property of another—including residential land, agricultural land, recreational land (such as a vehicle park), a building, an aircraft, or an automobile—without consent and if the person (1) had notice that the entry was forbidden, or (2) received notice to depart, but failed to do so.

The definitions and penalties for criminal trespassing vary from state to state and are usually located in a state’s penal or criminal code (statutes).

In Colorado, criminal trespassing is defined under the state's penal code and is considered a crime when a person unlawfully enters or remains on the property of another without consent. The offense can occur on various types of property, including residential, agricultural, recreational, as well as in buildings, vehicles, and aircraft. The severity of the offense and the associated penalties can vary depending on the circumstances, such as the type of property trespassed upon and whether the trespasser intended to commit a crime while on the property. For instance, first-degree criminal trespass (a felony) involves entering or remaining in a dwelling or a motor vehicle with intent to commit a crime therein. Second-degree criminal trespass (a misdemeanor) involves entering or remaining on agricultural land or premises of another. Third-degree criminal trespass (a petty offense) involves unlawfully entering or remaining on any other kind of property. Penalties can range from fines to imprisonment, depending on the degree of the trespass.