There is a cure. Our forefathers knew it well and even ensrined it in our Constitution.
"A well regulated militia, (thats trained not government controlled btw) being necessesary to a free state, the right of the people to keep and bear arms shall not be infringed."
Those people in that theater were certainly not free while the shooter controlled their actions. Had they all been armed, as intended by our founders, the shooter would not have walked in.
Shooters like him LIKE "gun-free zones"