Two comments....
First, looking at that sign....think it's 5 inches tall? I doubt it, based on the pic. Law says "at least 5x7 inches"...
Second, MKEGal posted something hoping the survivors would sue the salon, and mentioned the immunity bit and all that. Initially I disagreed (but did not post), because my interpretation and discussions with attorneys and other people in the know do not agree with that interpretation of the immunity clause. (Essentially my interpretation, upon which those I've talked to "off the record" agree, is the immunity being bestowed by the law is for the actions of people legally carrying. They are not granted that immunity if they post because there's nothing to grant immunity from - they didn't allow carrying so they can't be held liable for the actions of carriers who disregard the policy. Posting does not confer liability or responsibility to provide complete safety...if it did, every time you walked into a business, you'd get a TSA prostate exam and x-rays, and prices for goods/services would go through the roof.) However, in light of what's been made public in the subsequent days - I'm making a 180 on that position. As it turns out, everyone in that spa knew that they were having trouble. They had had specific discussions on locking doors and escape routes and such because of this individual - thus they did in fact know there was a specific threat. IMHO, the spa owner should have told Zina not to return to work until the situation was resolved....or hire a security guard or something.