Guns

Mass homicides are horrific tragedies. Society must do whatever's possible to understand them fully, so as to prevent them. But people also need to separate the data from the myths and the social, political and moral narratives that often form around crime.
What explains disparate public health threats such as senseless gun violence and anti-vaxxerism? The answer may come from Russian novelist Aleksandr Solzhenitsyn, who said that the West had become too focused on personal rights at the expense of duty to one's neighbor.
The game, Clue Master Detective, requires eight potential weapons. The CDC finds two are the most popular.
Race, age and other demographic factors are commonly controlled in epidemiology studies. It makes no sense to compare one group to another group if researchers do not bother to control for confounders – that is, factors like race or age that can cause researchers to draw the wrong conclusion.
The point isn't to scare people about accidental carbon monoxide poisoning, which kills, on average, 374 people per year. Given our population of 319 million, that's a minor threat. Instead, this is to show that the chaotic stuff that makes the nightly newscasts is far less likely to kill you than boring, everyday things.      
Gun violence is not solely about gun regulation or the environment. There are many nuanced contributors, including the social networks.