That doesn't actually disprove free will though? What if what he wants to do each time is rob the bank, and therefore he does it of his own free will? If you were to go to a mall and suddenly became hungry and you could only pick between two places to eat: McDonald's and KFC, but you hate McDonald's so you pick KFC. Now, you go there again two weeks later and suddenly you are hungry again, which of the two places will you pick?
But then his decisions would be predetermined.
It's a paradox, really. The only way you could possibly make a (non-random) decision is if the world is determined, which means that every decision you've ever made were already decided before you made them. Thus, the will is determined and not free.