My nephew is having problems with a neighbor trespassing on his property.  The guy hung a tree stand.  I'm trying to help him out.  I never owned hunting land, so I don't know the correct way to proceed.

Can he prosecute if he does not have "No trespassing" signs posted?

Regarding the tree stand.  He set up two trail cams on the stand.  One in paling sight but high, one about 25' higher, covering both the stand and the other camera.  His bro-in-law wanted him to take it down and give it to him.  I said that may escalate the issue.  Nephew wants to get photos, then call the cops.