This bill establishes an affirmative defense to prosecution for the crimes of criminal trespass and certain instances of aggravated criminal trespass when the person was at the time the person committed the act an unhoused person attempting to seek shelter in the dwelling place, structure, place, cemetery or burial ground the person entered or remained in. The bill defines "unhoused person" as a person who is without shelter or who lacks a fixed, regular and adequate nighttime residence.