The girlfriend of Las Vegas gunman Stephen Paddock has arrived in the United States, where she is due to be questioned by police.
Marilou Danley, who was in the Philippines, was met by federal agents when she landed in Los Angeles on Tuesday night.
Reports said Paddock transferred $100,000 (£75,400) to her in the Philippines before Sunday's shooting.
He killed 58 concertgoers and injured more than 500 in Las Vegas.
From his 32nd floor suite at the Mandalay Bay Hotel, the retired accountant - who had no criminal record - sprayed bullets into a crowd at a country music festival below, before apparently killing himself.
Police officials quoted by the Reuters news agency said they hoped Ms Danley - an Australian citizen who moved to the US 20 years ago - would consent to be interviewed voluntarily.
US authorities have named Ms Danley a "person of interest" in their investigation, , and said they made contact with her shortly after the shooting.
She had been in the Philippines since late September, local media reported.
Her sisters told Australian outlet 7News that Ms Danley had not known about the trip until Paddock told her he had bought her a ticket to the Philippines. "She was sent away... so that she will not be there to interfere with what he's planning," they said.
Paddock checked into the Mandalay Bay Hotel on 28 September, reportedly using some of Ms Danley's identity documents.
The Philippines' National Bureau of Investigation told AFP news agency it was investigating reports that Paddock sent $100,000 to Ms Danley in the Philippines days before the shooting.
Ms Danley's sisters also told 7News that she had been wired that amount in the Philippines.
An unnamed US official told Reuters news agency that investigators were assuming the amount was intended as a form of life insurance.
Eric Paddock, the youngest brother of Stephen Paddock, told the New York Timesthat his brother loved and doted on Ms Danley.
"She was probably one of the only people I've ever seen that he'd go out of his way to do a little thing for," he said.
But the pair are also said to have had a turbulent relationship, according to other reports. The Los Angeles Times has spoken to people who witnessed Paddock verbally abusing Ms Danley at a coffee shop in Mesquite, Nevada.
Police say Paddock set up a number of cameras in and around his hotel suite.
Two cameras in the hallway and one in the peephole allowed him to see if "law enforcement or security" were approaching, they said.
Although the authorities are still unable to explain why a 64-year-old gambler and retired accountant should want to carry out a mass shooting by hauling such a vast arsenal of weapons to the hotel, they do know there was a high degree of planning.
The authorities in Las Vegas revised the death toll down from 59 on Tuesday evening, saying that one of the bodies was that of the gunman.
Clark County Sheriff Joseph Lombardo told reporters: "It was pre-planned extensively and I'm pretty sure he evaluated everything he did in his actions."
Undersheriff Kevin McMahill suggested the attack may have stopped when Paddock was disturbed, shooting a security guard.
President Trump is in no doubt. He described Paddock as "a sick man, a demented man".
But a senior US homeland security official, speaking on condition of anonymity to news agency Reuters, said there was "no evidence" of "mental illness or brain damage".
Reports on Wednesday said Paddock was prescribed an anti-anxiety drug in June, but this has not been officially confirmed.
Nor have police found links to any foreign or domestic terrorist organisations, despite the claims made by the group known as Islamic State that the gunman was acting on their behalf.