I too saw this on my local news, as I live about 30 minutes from where this happened. He wanted to teach creationism as a mythology class. If the prof is a leftwing, anti-gun, tree worshiping hippie as he appears to be, then of course he would not be armed. It is against the law to carry a firearm in Kansas anyway.
I'm just glad his attackers did not have a firearm. That would have given even more fuel to the anti's.