There is a rationality link here, but it's not the one you were thinking of.
We’ve Seen This Movie Before - By ROGER EBERT
Should this young man — whose nature was apparently so obvious to his mother that, when a ABC News reporter called, she said “You have the right person” — have been able to buy guns, ammunition and explosives? The gun lobby will say yes. And the endless gun control debate will begin again, and the lobbyists of the National Rifle Association will go to work, and the op-ed thinkers will have their usual thoughts, and the right wing will issue alarms, and nothing will change. And there will be another mass murder.
Colorado Gun Laws Remain Lax, Despite Changes After Columbine
I think that the numbers for responsible gun owners still speak for themselves- No legally owned fully-automatic firearm in private hands in the US has been linked to a crime.
A Ph.D student in neuroscience shot at least 50 people at a showing of the new Batman movie. He also appears to have released some kind of gas from a canister. Because of his educational background this person almost certainly knows a lot about molecular biology. How long will it be (if ever) before a typical bio-science Ph.D will have the capacity to kill, say,a million people?
Edit: I'm not claiming that this event should cause a fully informed person to update on anything. Rather I was hoping that readers of this blog with strong life-science backgrounds could provide information that would help me and other interested readers assess the probability of future risks. Since this blog often deals with catastrophic risks and the social harms of irrationality and given that the events I described will likely dominate the U.S. news media for a few days I thought my question worth asking. Given the post's Karma rating (currently -4), however, I will update my beliefs about what constitutes an appropriate discussion post.