Nothing hurts the value of an autograph like murder ... which is why O.J. Simpson's got a big problem on his hands, so says "Pawn Stars" honcho Rick Harrison.
With Simpson arguably more famous now than ever before, the guys on the "TMZ Sports" TV show (airs weeknights on FS1) asked Harrison if he expects a spike in demand for O.J. stuff.
But Harrison says the exact opposite will happen -- and says if Juice is planning on making crazy money doing autograph signings at sports collectors shows ... he's BADLY mistaken.