"The AR-15, the civilian version of the military assault rifle (M16 or M4), has become the most commonly used rifle in US mass shootings; the recent shootings in Parkland and Las Vegas, for instance, testify to the effectiveness of this weapon’s design. It was made for the military, to allow members of the armed forces to better dispatch multiple enemies in short order; in the hands of civilians, it not only clearly serves the same purpose for some individuals, but it’s unclear what other purpose it could serve, given how and why it was made."