Why does Fix believe that Fogg is the robber?

In Inspector Fix's long experience as a policeman, all serious thieves are gentlemen. And the man who carried out the daring raid on the Bank of England is no exception. His crime has all the hallmarks of having been carried out by a gentleman thief, that is an independently wealthy man who steals out of boredom or for the sheer hell of it.
Fix immediately suspects Phileas Fogg of being the Bank of England thief; not only does he fit the description of a gentleman, but he suspiciously leaves the country not long after the robbery. So the intrepid Fix sets off in hot pursuit of the man he believes to have robbed the Bank of England. He follows Fogg on his epic journey across the four corners of the globe, hoping to make a name for himself as the man who caught the man who robbed the Bank of England.