As I understand it, "to be trespassed" is a term of art that basically means "the cops were called, told that person was trespassing, the cops duly informed that person they are trespassing & had to leave the property, and the person left, but was not charged". It's basically establishing a legal trail so that if the person refuses to leave or continues to trespass at that location in the future they have a better basis for charging them.