Trespassing and harassing from neighbor.

my neighbor trespassed been harassing us. He moved our plant and our stepping stone, then threw it down out on the street when we put it back to where it was. My kids were witnessed all his violent action and now they're scare to go out and play. He did this more than 2 times in the past. Please let me know what I have to do. He was accusing us that we were trespass his property, but we have document proof our where our property border line is. Please help. Thank you