No gun in the United States creates more controversy than an assault weapon--a military-style rifle, pistol, or shotgun available to the public. Yet, no consistent definition of an assault weapon exists, while attempts to outlaw or restrict these guns have created tremendous controversy over the rights of Americans to defend themselves and the question of how far the Second Amendment's freedoms extend. How are assault weapons used by everyday Americans? Millions exist in private ownership, yet they are most commonly held among several categories: police, criminals, and, most notoriously, mass shooters, who rely on assault weapons for overwhelming power against targets. While these weapons are less deadly overall than other guns, their ability to deal tremendous damage makes them a lightning rod for argument, analysis, and restrictions in the modern gun debate.