HELP - Personal Property Left by Previous Owner

[Christopher Cannon]

Sorry for the long post, but I've Never encountered this before - My partnership is in escrow on a SFR in California. It's a fantastic deal that I've spent 4 months developing a relationship with the current owner and the city attorney just to get it under contract. The short story is that the city removed the owner 2-3 years ago and the house was condemned as a health hazard. Under threat of having the property put in court receivership, the owner agreed to sell to me and the city agreed to allow me to renovate the property. Everything with inspections and DD has gone great - except the amount of personal property still left at the residence by the owner. Thats the problem - he's a hoarder. We close in 15 days and it's doubtful, despite my locating movers, that he gets his stuff out. Keep in mind all of it is junk and covered in mold - but I don't want to trash it for fear of the owner coming after me for destroying his property. At the same time - this is an amazing deal and I desperately want to close. I've prepared an addendum to the Purchase Agreement to address the personal property left after close of escrow, but to date he hasn't signed. My question(s) - what happens if we close and the owner leaves all his stuff? Do I rent a storage unit? If so for how long? How do I force him to take his property back? If anyone has encountered this problem (or squatters) - any insight is greatly appreciated.