That's never going to fly, especially in the current context.
It's a horrendous, senseless killing of innocent people which will definitely be assimilated to islamist/arab terrorism for a large part of the German population. This wretched piece of shit poured more oil on an already latent but intensely burning fire.
Just imagine the picture: even if they're highly educated and/or far-right, the Arabs' sole purpose is to kill Christians/white people/whatever you want to insert. Cue in the lack of integration, conflicting values, culture incompatibility, innate fanaticism, danger to the rest of the population and yadda, yadda.
Feck this asshole to hell and back. This will have massive consequences on the next elections. It's a shame that he didn't catch a bullet before he went on a rampage.