Because OJ was hiding all of his money from Fred Goldman, who won a $35 Million dollar law suit - Simpson had to be very shady and diabolical with his money.
He basically went "financially underground" and hide his millions in off shore accounts. Fred Goldman was relentless, and hired people to trail OJ's shenanigans.
What Simpson would do for quick cash was deal in sport memorabilia, and also sell his signature.
He traded in some of his own property for cash. Were these items legitimately his? Who knows? There were traded back and forth all the time, sold on E-Bay, and at auctions and shows.
The basic point is this: if they were his items, he could have gone to the police, but he didn't. Do you know why? Fred Goldman would have found out about it and seized the items and the money.
Moreover, you don't "get your stuff back" by bringing in thugs with guns, holding people at gunpoint, and threatening them.
What planet do you live on?
Fred Goldman got his revenge after all.
Please see post #27.