Hmmm... That’s strange...
If these guys aren’t Islamic, why didn’t he consider targeting a mosque? People there aren’t allowed to carry guns, and it would make the news too...
Hmmm... Maybe something is wrong with my assumptions...
He doesn’t want to be charged with a hate crime by attacking a mosque.
No doubt there are already plenty of guns and probably some RPGs and SEMTEX there, too. They are commonly referred to as "ammo dumps".