An undated photo of Las Vegas gunman Stephen Paddock, right, with his brother Eric.
The man suspected of the deadliest shooting spree in US history was described as a high roller, but authorities could not immediately determine if his gambling luck had gone way south.
Las Vegas casino records suggest thatStephen Paddock could actually have won tens of thousands of dollars in the weeks before he fired hundreds of rifle shots from a 32nd-story hotel window at a throng of country music fans below, a casino executive and a federal law enforcement official said.
But he also could have suffered big losses during the same period. That's one reason the FBI was still stumped late Monday on what led him to sneak an arsenal of rifles and ammo into his Mandalay Bay hotel room and unleash a murderous barrage of gunfire Sunday night, killing at least 59 people and wounding 527 more before taking his own life.
Paddock's brother was quoted as saying he was wealthy, liked to take cruises, gamble and go to shows in Vegas.
Drapes billow out of broken windows at the Mandalay Bay resort and casino Monday. AP
In the weeks before the massacre, Paddock filled out several required federal financial reports signalling that he either had won more than $US10,000 in a single gaming day or laid out a sum larger than that at the casino, said the federal law enforcement official, who spoke on condition of anonymity because the investigation is confidential.
NBC News, which first reported on Paddock's large transactions, said some of the Currency Transaction Reports, or CTR, recorded movements of funds exceeding $US20,000 and even $US30,000.
Under a provision of the Bank Secrecy Act, if someone plunks down $US11,000 in cash at a casino's roulette wheel, the casino is required to fill out a CTR because the sum exceeds the threshold of $US10,000.
The reports, which also are required if multiple transactions together top $US10,000 on a single gaming day, are turned over to the U.S. Treasury Department's Financial Crimes Enforcement Network and the Internal Revenue Service.
But the reports are not required if a gambler loses more than $US10,000. If Paddock lost heavily and didn't file transaction reports, investigators still might be able to track his gambling fortunes by watching hours of casino videos that record every bet at gaming tables.
Debris is strewn through the scene of a mass shooting at a music festival near the Mandalay Bay after the horror the night before. JOHN LOCHER
History shows no 'indication of being unfit'
Paddock lived in a modest home in nearby Mesquite, Nev., but had earlier lived in a town of the same name outside Dallas. He had investments in several real estate deals, including an apartment building in Mesquite, Texas, and an uncompleted real estate development in Henderson, Nev., south of Las Vegas.
In both cases, Peggy Paddock, which matches the name of his ex-wife, was listed among investment partners. Paddock also had owned two propeller airplanes, though he sold them several years ago, public records show.
Paddock had 16 guns in his hotel room when his body was found by police, according to law enforcement authorities; another 18 were found at his home, they said, plus various explosives, including ammonium nitrate, a common fertilizer that can be turned into a bomb.
Property records show that Paddock had lived with Australian citizen Marilou Danley, whom his brother, Eric, described as his girlfriend. Facebook
Christopher Sullivan, general manager of the Las Vegas retailer Guns & Guitars, said Paddock "was a customer and purchased firearms from our store" but "never gave any indication or reason to believe he was unstable or unfit."
He said that "all necessary background checks and procedures were followed, as required by local, state and federal law."
Sullivan, who said his store is cooperating with investigators, said he and his employees "mourn for this tragedy" and offer their prayers to the victims and their families.