Death coming sooner is, in itself, no more or less a moral issue than a train leaving the station early, before all the ticketed passengers have boarded.
The immoral act was shooting them, not failing to give them mosquito nets.
In case you're wondering why everyone is downvoting you, it's because pretty much everyone here disagrees with you. Most LWers are consequentialist. As one result of this, we don't think there's much of a difference between killing someone and letting them die. See this fantastic essay on the topic.
(Some of the more pedantic people here will pick me up on some inaccuracies in my previous sentence. Read the link above, and you'll get a more nuanced view.)
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.