US President Donald Trump and first lady Melania Trump board Air Force One as they depart Joint Base Andrews in Maryland, US, on their way to Las Vegas, 4 October 2017.
LAS VEGAS - Investigators probing the mass shooting at a Las Vegas concert planned to interview the gunman's girlfriend on Wednesday, a day after she returned to the United States from the Philippines, while her relatives told media she had not known of his plan.
Stephen Paddock, a 64-year-old retiree, killed himself moments before police stormed the hotel suite from which he unleashed Sunday night's attack. Paddock, who killed 58 people in the deadliest mass shooting in modern US history, left no clear clues as to his motive.
GALLERY: Las Vegas shooting spree
Law enforcement authorities were hoping to obtain some answers from the woman identified as Paddock's live-in companion, Marilou Danley. Clark County Sheriff Joseph Lombardo called her a "person of interest" in the investigation.
Danley, an Australian citizen reported to have been born in the Philippines, landed in Los Angeles on Tuesday night after taking a flight from Manila, where she had travelled to before the shooting rampage.
A police official in Manila, the Philippine capital, and a law enforcement official in the United States, both speaking on condition of anonymity, said Federal Bureau of Investigation agents were meeting Danley on arrival.
The US official said Danley was not under arrest but that the FBI hoped she would consent to be interviewed voluntarily.
Danley had assured her family she has a "clean conscience" following Sunday night's rampage, her brother told ABC News in the Philippines.
"I called her up immediately and she said, 'Relax, we shouldn't worry about it. I'll fix it. Do not panic. I have a clean conscience,'" Reynaldo Bustos told ABC in Manila.
Danley's sisters told Australia's Seven Network television that Paddock had bought Danley a ticket to the Philippines, a move they now believe was intended to allow him to plan his attack without interruption.
The network did not provide the sisters' full names.
"She probably was even shocked than us because she is more closer to him than us," one of the sisters told the network.
Investigators were examining a $100,000 wire transfer Paddock sent to an account in the Philippines that "appears to have been intended" for Danley, a senior U.S. homeland security official said on Tuesday.
The official, who has been briefed regularly on the probe and spoke on condition of anonymity, said investigators' working assumption was that the money was intended as a form of life insurance payment for Danley.
President Donald Trump, who strongly supported gun rights during his White House campaign, was travelling to Las Vegas on a condolence visit on Wednesday. The trip will be the first time that he has faced as president the aftermath of a mass major shooting of the type that has killed hundreds of people in recent years in the United States.
"It's a very, very sad day," Trump told reporters before leaving for Las Vegas, adding that the investigation was progressing. "They're learning a lot more, and that'll be announced at the appropriate time."
In Las Vegas, police said they did not yet know what motivated Paddock, who had no criminal record, no known history of mental illness and no outward signs of social disaffection, political discontent or extremist ideology.
Danley had been sharing Paddock's home in a retirement community in Mesquite, Nevada, about 145 km northeast of Las Vegas, according to police and public records.
She arrived in Manila on 15 September, flew to Hong Kong on 22 September and returned to Manila on 25 September. She was there until she flew to Los Angeles on Tuesday night, according to a Philippine immigration official.
A Philippine police source said authorities in Manila were told Paddock used identification belonging to Danley, who has an Australian passport when checking into the Mandalay Bay hotel on the Las Vegas Strip.
A total of 47 firearms were recovered from Paddock's hotel suite, his home in Mesquite, and another property associated with him in Reno, Nevada, according to Jill Snyder, special agent for the US Bureau of Alcohol Tobacco and Firearms.
Snyder said 12 of the guns found in the hotel room were fitted with bump-stock devices allowing the guns to be fired almost as though they were automatic weapons. The devices are legal under US law, though fully automatic weapons are banned for the most part.
More than 500 people were injured, some trampled in the pandemonium in Las Vegas.
The death toll far surpassed the massacre of 26 young children and educators in Newtown, Connecticut, in 2012, and the slaying of 49 people at a gay nightclub in Orlando last year. The latter attack was previously the deadliest mass shooting in modern US history.