Answer: The man must first place a coin in the center of the table. He then must replicate every move the serial killer makes on the opposite side of the table. Eventually the serial killer will run out of places to place a coin and the man will win.
You want to send a valuable object to a friend. You have a box which is more than large enough to contain the object. You have several locks with keys. The box has a locking ring which is more than large enough to have a lock attached. But your friend does not have the key to any lock that you have. How do you do it? Note that you cannot send a key in an unlocked box, since it might be copied.