Legal Question in Criminal Law in Pennsylvania

Re: trespassing

The defenses from the Statute itself probably cover your action.

(c) Defenses.- It is a defense to prosecution under this section that:

a building or occupied structure involved in an offense under subsection (a) of this section was abandoned;

the premises were at the time open to members of the public and the actor complied with all lawful conditions imposed on access to or remaining in the premises; or

the actor reasonably believed that the owner of the premises, or other person empowered to license access thereto, would have licensed him to enter or remain.