Maybe place a trail cam where he cant see it, if thats even possible. And when it catches him trespassing, you have the proof. I know in NY you cant kick a trespasser off the land, only the land owner can. I like Davidmil's idea, put up a big sign telling him he is being watch for trespassing, and if caught, he will be arested..... Confronting persistent trespassers is not recommended. He could be violent. Carry a camera with you at all times. If you do see him, take a picture, and leave. But make sure the picture is good enough to ID him.
If you know where he is parking get his plate number so they will know where to go to arrest him at home. Thats just my opinion.....