Update 2.38pm: The Las Vegas gunman who killed 58 people in the deadliest mass shooting in modern US history stockpiled weapons and ammunition over decades, and meticulously planned the attack, authorities believe.
Authorities, however, still do not know what led Stephen Paddock, 64, to carry out the attack.
On behalf of a GRATEFUL NATION, THANK YOU to all of the First Responders (HEROES) who saved countless lives in Las Vegas on Sunday night. pic.twitter.com/ZxuMYWnNHv— Donald J. Trump (@realDonaldTrump) October 5, 2017
"What we know is that Stephen Paddock is a man who spent decades acquiring weapons and ammo and living a secret life, much of which will never be fully understood," Clark County Sheriff Joseph Lombardo said at a recent news briefing.
Sheriff Lombardo said he found it hard to believe that the arsenal of weapons, ammunition and explosives recovered by police in their investigation could have been assembled by Paddock completely on his own.
"You have to make an assumption that he had some help at some point," the sheriff said.
Update 11.47am: Las Vegas police said there was evidence gunman Stephen Paddock intended to survive and escape his deadly attack at a country music festival on Sunday and speculated that he could have had assistance.
The police also revealed that he also rented an apartment overlooking another music festival that took place in the city the previous weekend.
The disclosures were among several new details revealed by Sheriff Joseph Lombardo, who also strayed into speculation that the man believed responsible for the deadliest mass shooting in modern US history had help.
Sheriff Lombardo said, “You’ve got to make the assumption he had to have some help at some point.”
He said that that the 64-year-old gunman rented a luxury room through Airbnb overlooking the Life is Beautiful music festival, another Las Vegas festival which occurred the week before the Route 91 Harvest music festival he targeted.
Sheriff Lombardo also said he had seen evidence that Paddock may have intended to survive his killing spree from the Mandalay Bay Hotel and Casino, which he used as a base for the attack. The sheriff did not say what such evidence was.
The remarks were made at a press conference held 72 hours after the attack, after extensively interviewing Paddock’s girlfriend, Marilou Danley, and examining Stephen Paddock's computers.
Mr Paddock’s killing spree resulted in 58 victims and injured at least 489 people. The updated casualty numbers were the most recent given by authorities on Wednesday night.
Earlier: The girlfriend of the Las Vegas gunman said she had no inkling of the massacre he was plotting when he sent her on a trip abroad to see her family.
Marilou Danley issued the statement after returning from her native Philippines and being questioned for much of the day by FBI agents still trying to figure out what drove Stephen Paddock to kill 59 people at a country music festival from his 32nd-floor hotel suite.
"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," Ms Danley said in a statement read by her lawyer outside FBI headquarters in Los Angeles.
Ms Danley, who out of the country for more than two weeks, said she was initially pleased when Paddock wired her money in the Philippines to buy a house for her family, but she later feared it was a way to break up with her.
"It never occurred to me in any whatsoever that he was planning violence against anyone," she said.
Ms Danley, 62, who has been called a "person of interest" by investigators, said she knew Paddock as a "kind, caring, quiet man" and hoped they would have a future together.
She said she was devastated by the carnage and she would cooperate with authorities as they struggle to get inside Paddock's mind.
Investigators are busy reconstructing his life, behaviour and the people he encountered in the weeks leading up to the deadliest mass shooting in modern US history, FBI Deputy Director Andrew McCabe said. That includes examining his computer and mobile phone.
But as of Wednesday, investigators were unable to come up with a motive for the Sunday night attack that left more than 500 people injured and ended with Paddock killing himself in his room at the Mandalay Bay hotel casino.
"This individual and this attack didn't leave the sort of immediately accessible thumbprints that you find on some mass casualty attacks," Mr McCabe said.
The 64-year-old high-stakes gambler and real estate investor specifically requested an upper-floor room with a view of the music festival, according to a person who has seen hotel records turned over to investigators.
The room, which goes for $590 (€500), was given to Paddock free because he was a good customer who wagered tens of thousands of dollars each time he visited the casino, the person said.
It was just another indication of how methodically he planned the attack. Authorities have said he brought 23 weapons in 10 suitcases into the room and set up cameras inside and out to watch for police closing in on him.
But investigators had little to work with in trying to determine what set him off.
"He was a private guy. That's why you can't find out anything about him," his brother, Eric Paddock, said from his home in Florida. As for what triggered the massacre, the brother said: "Something happened that drove him into the pit of hell."
Paddock had no known criminal history. Public records contained no indication of any financial problems, and his brother described him as a wealthy real estate investor.
"I believe, based on what I have been told, the issue was not that he was under financial stress," said Senator Claire McCaskill of Missouri, the ranking Democrat on the Homeland Security Committee.
President Donald Trump and first lady Melania Trump met privately with victims at a Las Vegas hospital on Wednesday and then with police officers and dispatchers, praising them and the doctors who treated the wounded.
"Our souls are stricken with grief for every American who lost a husband or a wife, a mother or a father, a son or a daughter," he said. "We know that your sorrow feels endless. We stand together to help you carry your pain."
Paddock had stockpiled 47 guns since 1982 and bought 33 of them, mostly rifles, over the past year alone, right up until three days before the attack, Jill Snyder, an agent with the federal Bureau of Alcohol, Tobacco, Firearms and Explosives, told CBS on Wednesday.