Let's turn this around. You decide to leave your new 42" HDTV with me so it doesn't get damaged in storage. After 18 - 24 months, life is settled enough that you want your stuff back. But, well, I just didn't want that HDTV hanging around so I sold it for funds to upgrade my own home theatre system... or put a hi-performance gearbox in my truck. I waited all of a year, so what's the beef?
This is how people find themselves charged with theft, felony theft, embezzlement and/or fraud.
Do some research on the web. Google his name - you might find likely addresses for him if he's paying for utilities somewhere. Send letters asking him to claim his property by [date-60-days-from-now] or it'll be sold. Lastly, ask your lawyer if taking out a brief ad in a Florida paper or two declaring property of firstname middleinitial lastname
will be sold in 60 days unless he calls a number will help show you made honest attempts to notify him.