Police: Las Vegas Shooter Had 42 Guns in Hotel, Home

Police investigating America's deadliest mass shooting say they have found a total of 42 guns belonging to Las Vegas gunman Stephen Paddock—19 in his Mesquite, Nev., home, and 23 in the Mandalay Bay Hotel and Casino hotel room that he fired into a concert crowd from, killing at least 59 people. Law enforcement officials say they found multiple loaded high-capacity magazines in the hotel room, suggesting the death toll could have been even higher if police had arrived later, ABC reports. His arsenal included high-powered rifles capable of penetrating police armor, officials say. More:

• Bump-stocks. Officials tell the AP that Paddock had two "bump-stock" devices capable of converting semi-automatic weapons into fully automatic firearms. Weapons expert Massad Ayoob tells the Guardian that the devices are legal but serious shooters tend to avoid them because they reduce accuracy. But that would not have been a problem for Paddock, who was "hosing a two-acre area with 30,000 targets," Ayoob says.

• Ammonium nitrate. Police, who have been searching a Reno property belonging to Paddock as well as his hotel room, vehicle, and Mesquite home, say they found several pounds of the bomb-making ingredient ammonium nitrate in his car, NPR reports.
• Rifles on tripods. Federal law enforcement sources tell the New York Times that the weapons found in Paddock's hotel room included two rifles with scopes set up on tripods in front of two windows. One official says his arsenal included AR-15-style assault rifles.
• Legal machine guns. Wired looks at the different ways in which Paddock could have achieved such a deadly rate of fire, They include bump-stock or "gat crank" devices, illegal modifications to turn semi-automatic weapons into automatic ones—or buying one of the hundreds of thousands of machine guns that were made before the 1986 ban on such weapons and are owned by civilians in the US. The right to own those weapons was "grandfathered in."
• Background checks. Two Nevada gun shops have confirmed to NBC that they sold Paddock guns in the last year. They say he passed the necessary background checks and staff would not have sold him the guns if any "red flags" had been raised. "We're very sad about the news of this tragedy. We're in the business of selling firearms legally and took all precautions on this sale, as we do with all sales," says David Familgetti of the New Frontier Armory in North Las Vegas.

(Neighbors say Paddock seemed normal, apart from his gambling.)