Confusion Between Gerasenes & Gadarenes With The Demon Possessed Man?

In Matthew it says "Gadarenes" while in Mark and Luke it says "Gerasenes." There are two possible explanations for the difference in spelling. First, there could be a minor scribal copying error on the spelling as there are different spellings in different manuscripts.  Second, Gadara may well have been the capital of the region in the Gerasenes and Matthew may have simply referred to it by a more local term: the Gadarenes. (CARM.)