The Las Vegas shooter, identified as Stephen Paddock, attached a “bump-stock” to 12 firearms to allow the semi-automatic rifles to mimic fully automatic gunfire, Rhe Associated Press reported.
The Bureau of Alcohol, Tobacco and Firearms made the revelation on Tuesday, putting an end to speculation that Paddock may have used fully automatic weapons in the shocking attack that left 59 people dead and more than 500 injured.
In total, police recovered nearly 50 guns, including rifles, shotguns, and pistols, from three locations, including the Mandalay Bay hotel where the shooter rained down hundreds of rounds on concertgoers attending a nearby country music festival.
— Jacqui Heinrich (@JacquiHeinrich) October 3, 2017
The AP explains how a bump-stock works:
The device basically replaces the gun's shoulder rest, with a “support step” that covers the trigger opening. By holding the pistol grip with one hand and pushing forward on the barrel with the other, the shooter's finger comes in contact with the trigger. The recoil causes the gun to buck back and forth, “bumping” the trigger.
Bump-stocks are legal because the device technically uses physics to increase the rate of fire and still requires one trigger pull for each round fired. Therefore, weapons equipped with the device are still considered semi-automatic.
Las Vegas Undersheriff Kevin McMahill told reporters on Tuesday that Paddock fired on innocent people for up to 11 minutes. The first gunshots were reported at around 10:08 p.m. and the gunfire ceased at 10:19 p.m. on Sunday.
It was also revealed that Paddock set up two cameras in the hallway outside his hotel room so he could see police or security approaching. Paddock killed himself before police could engage him.