"Mass Shooters’ Weapon of Choice"

"One common denominator behind these and other high-casualty mass shootings in recent years is the use of assault style rifles, capable of firing many rounds of ammunition in a relatively short period of time, with high accuracy. And their use in these types of shooting is becoming more common: There have been eight high-profile public mass shootings since July of last year, according to a database compiled by Mother Jones magazine. Assault-style rifles were used in seven of those.
In the past 10 years, assault-style rifles have been used in 14 public mass shootings. Half of those shootings have occurred since last June."

In the wake of the Orlando massacre, Christopher Ingraham in The Washington Post discusses the growing popularity of rifles like the AR-15.