Neighbor harassing workers

[Alazar Wubet]

Hey guys,

I've been working on a flip for a while and we're almost done with the project with only final items remaining. Our next door neighbor is deceased, according to property records and we always thought the property is vacant but someone showed up and started throwing bricks at the new sliding door we installed, my workers heard the loud noise and went to check and they claim to see a weapon on his hand and fled the property. 

He then Entered through the open door and kept on screaming "come to the door" and went inside and started walking the property while smoking. 

i immediately called the police and they came within 2 minutes and gave him just a warning and left. They told me they'll arrest him if he trespassed again. He immediately came back and started throwing large tree branches and other stuff on to my deck. 

i called the police a second time and they came and arrested him and gave me the report number.

i have a security camera video of him throwing the brick, walking in and out of my property, screaming, and throwing the branches.

what do i do to protect my workers and not lose my investment. Is there anyone that has had the same experience, even remotely?