We bought a home that had a nice washer and dryer included with it per the disclosure. They were still there when our realtor did the final walkthrough, then walked off before we took possession. 
Then on the next house the AC unit was stolen between final walk through and closing. 
This obviously gets expensive and I suspect as society slides it’ll only become more common. How can I prevent this? Is there a way to have locks changed and kept by a third party as part of the final walk through? Or could I add a clause that allows me to put up some cell signal security cameras to protect an item like the AC condenser during that time? 
Or is it acceptable to require a walk through the morning of closing? I’d really like that…