if anything, the patrons should be held responsible... because of mass shootings in other places, they should have foreseen the possibility of a mass shooting... and then to go to a theatre that does not allow firearms, they should have foreseen an even greater possibility of a mass shooting...
The pateons obeyed the law.
The theater owner disarmed them. The theater owner, and other negligent establishments who disarm their patrons, should be sued out of business.