From Slate.com:

Media stories in the wake of mass shootings typically feature a laundry list of mistakes that reflect their writers’ inexperience with guns and gun culture. Some of them are small but telling: conflating automatic and semi-automatic weapons, assault rifle and assault weapon, caliber and gauge—all demonstrating a general lack of familiarity with firearms. Some of them are bigger. Like calling for “common-sense gun control” and “universal background checks” after instances in which a shooter purchased a gun legally and passed background checks. Or focusing on mass shootings involving assault weapons—and thereby ignoring statistics that show that far more people die from handguns.