Things that we can do about this: 1) Firearm control - complicated political issue, with reasonable people on both sides of the issue. And even if there were

Things that we can do about this: 1) Firearm control - complicated political issue, with reasonable people on both sides of the issue. And even if there were federal (executive, legislative, and judicial) political unanimity on action (there is not and can't be for decades), it remains a larger practical problem than in any country that has so far banned guns. State and city-level action has not proven very effective. 2) Political control and censorship - only a fraction of these killers seem to be radicalized, and they generally seem to be lone-wolves. It seems a course ripe for abuse. 3) Drug enforcement - it has been pointed out that almost all of these killers have addiction problems of some kind. Anti-depressants may also play a role. But drug use seems too tenuous a connection, and these substances are used by such a broad swath of the population without this effect, that it would be hard to fix this with drug enforcement alone. 4) Psychological intervention - could the right sort of intervention at the right time avert these killings? It's hard to believe not, but since we can't predict the killings, we can't do much here. But if we had better knowledge, it's possible to imagine something as simple as voluntary social media guidelines (for 24-hour news, Google, Twitter, Facebook, etc.), that might alleviate the problem. Or something far more heavy handed and open to abuse or misuse, including high school psychological testing and reporting, mandatory social services checkups, etc. If I were an engineer tasked with solving this problem, I would try the full-court press solution on all of these, rather than fixating on any one component. Solution "4" is the most interesting to me, because it seems the least explored, and the place where increased knowledge and new techniques could possibly have the greatest effect. I think that we should be especially interested in how exactly people become killers, whether there are multiple types (there certainly are), and what are the necessary stages in the process. Studies like this are especially vital and interesting to me, and we need to spend far more effort on this type of research. The biggest danger that I can see is that political and emotional energy on the impossible solutions prevent useful action anywhere. EDIT: More on this study. The nice data fit on their contagion equation is very interesting because it begs to be expanded. The "contagion" is mediated by the media somehow. Is it as simple as reading stories about other shootings leading to more? Or is there a media climate effect? What other types of media can lead to shootings, etc. It would be tremendously helpful to learn enough to be psychologically precise about all of this.