FBI Deputy Director Andrew McCabe told CNBC on Wednesday that the lack of a clear motive was a "surprise" in this mass shooting.
Authorities say shooter Stephen Paddock put a camera in a food service cart outside his hotel room to see if anyone was coming to take him into custody. At least 20 of the survivors admitted to one of several hospitals in the area, University Medical Center, remained in critical condition on Tuesday, doctors said.
After Paddock gunned down the concertgoers, he then turned a gun on himself.
In total, 59 were killed and more than 500 injured, making it the worst mass shooting in American history.
Snyder said authorities would not have been notified of the rifle purchases but would have been informed if two or more guns were bought at one time.
Authorities previously disclosed that he had such "bump stock" devices with him at the hotel. She had traveled to Hong Kong and Manila in the days before Paddock's attack.
Paddock had wired $100,000 to the Philippines, a law enforcement source said. There were no immediate details available about those trips.
A police official in Manila and a law enforcement official in the United States, both speaking on condition of anonymity, told Reuters that Danley left the Philippines unescorted but was being met by Federal Bureau of Investigation agents in Los Angeles.
"Beefed up security procedures are continuing throughout the resorts". "Only Marilou can maybe help to solve this investigation and what and why he's done this". "I didn't even know he knew about guns", Mr Knights said. A 42-year-old U.S. Army veteran who served as a sniper in Iraq immediately began tending to the wounded.
"He was a gambler and a speculator, and he did that in Vegas", said Don Judy, who lived next door to Stephen Paddock from 2013-2015.
Jordan Knights' aunt is Marilou Danley, a 62-year-old who recently returned to the United States from a weekslong trip overseas.
Ah, the classic quiet, nice guy behavior we all know and love: Being such a dick to your girlfriend that the people who work at Starbucks remember you for it after you murder dozens of people.
Knights told Australia's Channel 9 from his home near Brisbane, "It seemed like he just looked after my aunty and that was it. But that won't be to compensate the 59 peoples' lives".
Eric Paddock said she might not be able to give investigators the clues they are hoping for.
Paddock's girlfriend has since touched down in the USA after flying from the Philippines to be interviewed by the FBI as part of the ongoing investigation.
Danley had been out of the country for weeks before the shooting.