Las Vegas, October 3 (RHC)-- In the U.S. city of Las Vegas, the toll in Sunday night’s mass shooting rose overnight to 59 dead and 527 wounded, as investigators searched for clues about what drove 64-year-old Nevada resident Stephen Paddock to carry out the worst massacre in modern U.S. history. 

Police say they found Paddock dead of a self-inflicted gunshot wound shortly before midnight Sunday after they used an explosive to break into his suite on the 32nd floor of the Mandalay Bay hotel, where he was holed up. 

The shooter reportedly used a hammer to smash a pair of windows and set up two high-powered rifles with scopes on tripods overlooking the Route 91 Harvest country music festival below, where he fired into a crowd of more than 20,000 concert-goers.  Paddock had at least 23 firearms in his hotel suite, and a further 19 guns were later found at his home, along with explosives and thousands of rounds of ammunition. 

Paddock had no criminal record and was able to purchase his arsenal legally.  Gun experts believe he may have used a trigger device -- available for purchase on-line for as little as $40 -- that can turn a semi-automatic assault rifle into a fully automatic machine gun.