it's marguerite oswald, the assassin's mother, who orders the headstone to be placed atop her son's grave>> it happens to be the tombstone of the most famous assassin in the history of western civilization. >> like many notorious figures in history, oswald's grave attracts the grimly curious. and that presents the next big plot point in this "strange inheritance" story. in november 1967, on the fourth anniversary of the jfk assassination, oswald's headstone goes missing. the caper is quickly solved when the father of a teenager in bartlesville, oklahoma, turns in his son and a friend. >> they came down as a prank, stole that tombstone, and were showing it off to a bunch of their high school buddies. >> it's returned to marguerite oswald, but never to the cemetery. she substitutes a more austere design. >> on the grave, she put a different headstone that was less attractive and much heavier. >> but what does marguerite do with her son's original, ornate gravestone? and how in the world, decades later, do the heirs in this "strange inheritance" tale end up with it? this is where the stories