I just got asked not to walk on a seemingly public sidewalk. Being as sensitive as I am it upset me a great deal. I would like to know how to find out who owns the apartments I was walking by and who to contact to force him to post a no trespassing sign if he indeed has the right to not let anyone walk on that sidewalk?
I don't think there is any way to force a person to post a no-trespassing sign, but you might motivate them. Trespassing laws are state-specific, for example in Washington the law is RCW 9A.52.080, and if you violate the law, it is a misdemeanor. If you are prosecuted, RCW 9A.52.090 provides a defense if
(2) 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 (3) The actor reasonably believed that the owner of the premises, or other person empowered to license access thereto, would have licensed him or her to enter or remain;
If it is reasonable to believe that the sidewalk is public then it is reasonable to believe that you are licensed to remain on the premises (the sidewalk).
A sign makes is clear that there is no permission to be be on the sidewalk. There are other indications, such as being behind a fence – also, being told that you are trespassing. If you reasonably believe that you have been told by the owner or person authorized by the owner, then the reasonable belief defense is not available. So the question is whether you have a reason to think that the person telling you this has authority.
You may be able to determine who owns the property by checking the assessor's office for the address, which may reveal a name and mailing address of the owner. You might inquire at the office, if there is an office. If the person in the office tells you not to trespass, they you would reasonably conclude that you have officially been put on notice.
There are at least 49 other versions of this scenario.