Keeping movie theaters as gun-free zones

I would like to know whether guns were banned from theater or whether the arrest of this guy was just precautionary.  From the LA Times:

A lawyer says there could be a simple explanation for why an Ohio man allegedly armed himself to the teeth for a Saturday night screening of "The Dark Knight Rises": He wanted the protection.
Scott A. Smith, 37, of North Ridgeville allegedly packed a bag with a loaded 9-millimeter Glock, extra ammunition clips and four knives for his trip to the movie theater, according toCleveland.com.
A search of Smith's home following his arrest turned up additional weapons, according to another report on Cleveland.com. That report said those items included eight rifles and handguns as well as "survivalist's gear" such as gas masks and bulletproof vests. The site additionally said that Smith was believed to have spent some time in the military.
It was the bag that caught the eye of an eagle-eyed, off-duty police officer who was working security on Saturday night at a movie theater in Westlake, Ohio, the news site reported.
That and the fact that the patron arrived extra early and took a seat with his back to the wall at the top of the theater, a position that Westlake Police Lt. Ray Arcuri said gave Smith a "tactical advantage." . . .