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 Indiana, criminal trespass is defined under Indiana Code 35-43-2-2. A person can be charged with criminal trespass if they knowingly or intentionally enter or remain on someone else's property without permission. This includes residential, agricultural, and recreational land, as well as buildings, aircraft, or vehicles. There are two key elements for this offense: (1) the individual had notice that entry was forbidden, or (2) after entering, they were asked to leave but failed to do so. Notice can be given in various forms, such as verbal communication, posted signs, or fencing. Penalties for criminal trespass in Indiana can range from a Class A misdemeanor to a Level 6 felony, depending on the circumstances, such as if the trespassing occurs on a scientific research facility, a key facility, or causes property damage. The severity of the penalty is also influenced by the trespasser's criminal history and whether the trespass led to an injury.