What constitutes defiant trespass in NJ?

Arrangements with my Godson's (now) ex-girlfriend were made to pick up her motorcycle and title. The bike was parked on the street in front of my house. The title was left in the mailbox. She proceeded to come onto the property (unescorted & without permission), open the garage and help herself to items that she felt were her property. I was in the house at the time & did not know she had entered the garage until my Godson told me (he heard her go in the garage). I went outside & immediately told her to leave my property & leave the items. She refused & two individuals she was with carried her back to the street. After calling the police, the one officer told me she can't be charged with trespass unless she's been told she doesn't have permission to be on the property.