"Among the six deadliest mass shootings in the last six years, the only one not carried out with an AR-15 style rifle was the Orlando nightclub attack two years ago that left 49 dead. The gunman, Omar Mateen, had a Sig Sauer MCX semiautomatic rifle, which shares features with the AR-15, though it functions via a different semiautomatic design — and is just as deadly. All of these military-style semiautomatic weapons have something else in common. They have been heavily marketed as home-defense and marksmanship weapons, and their sales have been a major driver of profits for gun manufacturers over the past two decades."