You need to get some sort of USB pen camera that records sound and video for cheap on Ebay (I have one I bought for $40 shipped from Tiawan) and the next time you see him, turn it on and record the sound and video of what he says. Then download it to the PC, and call the cops then a lawyer. The cops will be forced to do something about any threats made when they see and hear them for themselves. You won't have to wait for a judge to act, they should arrest him immediately. After this happens, immediately take the video to a lawyer and/or judge and have a restraining order of some sort placed on him barring him from the apartment and your presence until you move out. Change the locks, too.
Also, if you can afford it and don't want more direct conflict, you can also install cheap spy cameras around the apt and set him up to get what you want. Tell him you need to go out of town for a day or 2, and make sure he knows you are all going to be gone. Then rent a hotel if you need to and catch him in the act of vandalizing your property. If you use an internet camera system, you can even monitor the apt from a hotel using a laptop. Then sue his ass off in court when you get him on video and most likely force him to sell some of his properties to settle or pay off the lawsuit. Good luck.