Do you mean they don't allow employees to carry, or they don't allow customers? (In NC they need a special sticker on the door, which our local store lacks, heh heh)
Blockbuster seems to go through a lot clerks who get shot. I know there was one here in Raleigh a year or so ago. Same MO, perp arrives before closing, shoots clerk. In that case, I don't think they even knew till the next morning.
What I am proposing is that some attorney focus on the negligence of that policy that resulted in four deaths in this instance alone. Blockbuster has made its no weapons policy public and as such they have increased the chances of such incidents happening in their stores.
Stay well - Stay safe - Stay armed - Yorktown