I'm betting it's someone from one of the known races who dyed his fur (To avoid being linked to the murder). Definitely not a fennec, and probably not a arctic either (His ears are pointy instead of round-ish)
Another option is that he's a red with unusual fur color (There have been quite a few in the comic after all, although beyond a cross fox most simply had some gray fur here and there).
Seeing how this guy was kinda hidden in shadows (So details aren't visible), he could very well be a silver fox or the like.