The girlfriend of mass murderer Stephen Paddock has said she had no idea what her partner was planning.
Marilou Danley said she was "devastated" by the massacre on Sunday night, which left 58 dead and more than 500 injured.
Paddock's girlfriend returned to the United States from the Philippines, landing in Los Angeles on Tuesday evening and was met by FBI agents eager to hear whatever she might know about the motive.
In a statement read by her lawyer, she described the gunman, who planned his attack meticulously as having been "kind, caring and quiet".
“I knew Stephen as a kind, caring, quiet man,” the statement read. “I loved him and hoped for a quiet future together. He never said anything to me, or took any action that I was aware of that I understood in any way to be a warning that something horrible like this was going to happen.”
“It never occurred to me in any way whatsoever that he was planning violence against anyone,” it added.
Although the FBI was eager to talk to her, Ms Danley, 62, is not in custody and it was made clear that she is not a suspect but a "person of interest" to investigators, and is free to go wherever she wants. She is an Australian citizen who moved to the United States 20 years ago to work on the casino strip.
She was out of the country on Sunday when Paddock opened fire on concertgoers using an arsenal of high-powered rifles he had stashed in his suite on the 32nd floor of the Mandalay Bay hotel on the Las Vegas Strip.
However, the authorities are investigating whether she was the recipient of the $100,000 Paddock wired to the Philippines recently — and if she was not, they hope she can tell them who was.
Investigators are trying to track that money and are also looking into at least a dozen financial reports over the past several weeks that said Paddock had gambled more than $10,000 per day.
US President Donald Trump arrived in Las Vegas on Wednesday to meet survivors of the massacre and the emergency services.
"We're going to pay our respects and to see the police who have done really a fantastic job in a very short time," the president said as he departed the White House with his wife, Melania. "It's a very, very sad day for me, personally," he added, saying he would be spending time with "some of the folks that are recovering, some of the survivors," and seemed emotional as he spoke about the human toll.
"We're going to be seeing — ah it's a very, it's very, it's a very — horrible thing, even to think about. Really horrible," he said. .
They arrived in Las Vegas at 9.30am and when asked about the shooter, the president replied, "Yeah, they [the police] are learning a lot more. That will be announced at an appropriate time."
Mr Trump has a long personal connection toLas Vegas, where he has a hotel. He also campaigned extensively across Nevada during his presidential campaign, drawing large crowds to rallies along the Las Vegas strip.
Retired FBI profiler Jim Clemente speculated that there was "some sort of major trigger in his life — a great loss, a break-up, or maybe he just found out he has a terminal disease." He also noted a possible genetic component to the indiscriminate killing: Paddock's father was a bank robber who was on the FBI's most-wanted list in the 1960s and was diagnosed as a psychopath.
Paddock, however, has no apparent history of mental illness and apart from a minor traffic offence, had never come to the attention of the police. Investigators say a great deal of planning went into the attack. Paddock checked into the hotel four days beforehand, meaning he could have taken in his vast arsenal of weapons in stages without attracting attention. He had also installed a camera in the peephole of his room door and two more in the hallway.
"I anticipate he was looking for anybody coming to take him into custody," said Sheriff Joe Lombardo
Paddock fired through the door of his hotel room and hit a security guard in the leg. But when a SWAT team stormed the room where he had been staying since September 28, they found he had killed himself.
US officials have reacted cautiously to a claim by ISIL that Paddock carried out Sunday night's massacre on its behalf.
— 'Mind of a psychopath' —
Authorities have seized 47 firearms from three locations, but found nothing to explain Paddock's actions.
"For this individual to take it upon himself to create this chaos and harm is unspeakable," Sheriff Lombardo said.
The carnage Paddock unleashed already appears to have inspired a copycat. Police in Oklahoma said they had arrested a man who threatened to carry out similar shootings in Oklahoma City and San Antonio.
Roderick Lamar Robinson, 39, was arrested on Tuesday in the Oklahoma City suburb of Warr Acres after several people alerted police to threats he had posted on Facebook.
As the identities of Paddock's victims began to emerge so too did stories of individual bravery.
Bruce URE, deputy police chief of the small Texas City of Seguin, was in the concert's VIP section when the gunfire broke out. He took shelter between two buses and tended to three people who had been shot, loading the bleeding strangers into a passing car and riding with them to hospital.
"They were all crying, and I was too," he said. "They were saying 'We're going to die, we're going to die,' and I still remember telling them: 'Not tonight, not tonight. Tonight's not your night. You're going to be OK.' Because I truly believed it."
While the White House has rebuffed calls to reopen the fraught US debate on gun control, Congress did shelve a controversial plan to make it easier to purchase gun silencers and make it more difficult to classify certain ammunition as "armour-piercing."
— 'Two doors from a lunatic' —
Paddock's neighbours in Mesquite, Nevada, 130 kilometres northeast of Las Vegas, were dumbfounded to discover the killer lived in their midst.
"We've never even thought about locking our doors," said Rod Sweningson. "We didn't know we lived two doors down from a lunatic."