How long do I have before I own someone else's property?

I have a friend that had up and walked out of their apartment and left everything behind. Another friend and I were asked to deal with the remaining stuff left behind. I had taken a 56" tv that he had asked me to hold onto until he could return to pick it up. Well, it's been over a year and a half, and I still have this tv. In the last couple of weeks I have asked him to find someone to come take it for him, as I don't have the room to store this tv anymore since I was finally going to just get my own big tv. He got upset when I gave him a deadline and told him that I would have to get rid of it if he didn't pick it up at that certain time. He started threatening me that he was going to take me to court if I got rid of the tv since it's his property. What do I do here? I've had this tv in my possession for over a year a half now, am I titled to any right in this case? Ever since I told him that he had so many days to get this, he has stop talking to me. I have no clue on what I can or cannot do. I even offered to put it into a storage unit for him, but I was told by the storage company that it would all have to go into my name, and I don't want the responsibility of this, especially if he doesn't make the payments on the storage. If you could please me if I have any rights in this that would be wonderful. Thanks so much for your time.