• Ms. Danley returned to the country late Tuesday night, landing at Los Angeles International Airport on a flight from the Philippines, officials said. Ms. Danley, who has been described by the sheriff of the Las Vegas police as a “person of interest” in the case, was met by F.B.I. agents, according to a law enforcement official.
• Mr. Paddock, a high-stakes gambler, wired thousands of dollars to the Philippines just days before the shooting, a federal official said. The authorities would not confirm to whom the transactions were intended.
• The police on Tuesday revised the number of victims killed on Sunday to 58. All but three of the people have been identified. These are some of their stories.
• President Trump was visiting Las Vegas on Wednesday. “We’re going to pay our respects and to see the police who have done really a fantastic job in a very short time,” he said as he left the White House on Wednesday with the first lady, Melania Trump.
The gunman’s girlfriend has returned to the U.S.
Ms. Danley boarded a flight from Manila to Los Angeles on Tuesday, according to Antonette Mangrobang, a spokeswoman for the Philippine Immigration Bureau.
The authorities, who met Ms. Danley at the Los Angeles airport, have called her a “person of interest” in the shooting investigation, which does not necessarily mean that she is suspected of committing a crime. She was out of the country when the shooting occurred.
More than three hours after her flight came in from Manila, an airport police officer confirmed that she had been taken out of the terminal through a side exit.
In an interview with ABC News, Reynaldo Bustos, Ms. Danley’s brother, said he had spoken with her after the shooting. He said she told him not to panic and that she had a “clean conscience.”
Ms. Danley met Mr. Paddock when she was working at a Nevada casino and he was a high-limit player, casino employees said. She worked at the Atlantis Casino Resort Spa in Reno from 2010 to 2013, according to her LinkedIn account.
John Weinreich, an executive casino host at the Atlantis Casino Resort Spa at the time, said he believed that Ms. Danley frequently attended to Mr. Paddock, serving him food and pointing out which machines might be ripe for a payout, eventually becoming his regular host. Read more about Ms. Danley here.
Body camera footage captured the officers’ response.
Las Vegas police officers took cover and directed concertgoers to safety as gunshots rang out on Sunday, newly released body camera footage shows.
“Hey, you guys, get down,” one officer shouted at bystanders between volleys of gunfire. “Go that way. Get out of here. There are gunshots coming from over there. Go that way.”
But some people did not believe they were under attack and rebuffed orders to evacuate. “That’s fireworks,” one bystander shouted at officers. Another yelled expletives when told to take cover.
As sirens blared and gunfire crackled, the video showed, officers strained to find the source of the shots.
“Hey, they’re shooting right at us, guys,” one officer said as he and his colleagues crouched behind a wall with their weapons drawn. “Everybody stay down, stay down.”
“North of the Mandalay Bay, it’s coming out of a window,” another officer says.
The three-minute video released by the police on Tuesday was a compilation of footage from the cameras of several officers at the scene.
“There’s multiple people shot up there,” someone says in one clip.
“We see muzzle blasts from the Mandalay Bay,” someone, apparently an officer, said in another clip.
The police have also confirmed the authenticity of leaked photographs of the deceased gunman with a revolver by his side and of his hotel suite, showing ammunition and rifles.
The gunman had stockpiled weapons.
Mr. Paddock, 64, had been buying weapons since 1982, including 33 in the past year, Jill A. Snyder, the special agent in charge of the San Francisco office of the federal Bureau of Alcohol, Tobacco, Firearms and Explosives, told CBS on Wednesday.
Asked if such purchases would set off any alarms, she clarified that the bureau would not have been alerted. The Gun Control Act of 1968 requires sellers to report the sale or disposition of two or more handguns to the same buyer, only if those purchases occur at the same time or within five business days of each other. There is no federal law requiring sellers to alert the bureau to the sale of multiple rifles.
Twelve of the rifles Mr. Paddock had in his luxury suite on the 32nd floor of the Mandalay Bay Resort and Casino were outfitted with a “bump stock,” a device that enables a gun to fire like a machine gun, with hundreds of rounds per minute, which may explain how he was able to rain such devastation on the crowd below, law enforcement officials said.
Such devices are generally legal, and the possibility that he may have used them set off a fresh round of calls by Democratic lawmakers in Washington to pass more gun regulations after the tragedy.
Semiautomatic rifles, like those the gunman had, are made to fire a single round with each pull of the trigger. But recordings and witness accounts of the shooting made it clear that Mr. Paddock was firing much faster, at a rate comparable to that of a fully automatic weapon, which quickly fires round after round with a single pull of the finger. Undersheriff Kevin McMahill of the Las Vegas police said that Mr. Paddock fired on the concertgoers for nine to 11 minutes, in about a dozen bursts.
The police have found a total of 47 firearms in his two houses and the hotel suite. Ms. Snyder said on Tuesday that almost all had been traced, and that they had been bought in Nevada, Utah, California and Texas.
Mr. McCabe of the F.B.I. dismissed “dubious claims of responsibility” — a reference to statements from the Islamic State group claiming that the killer was one of its followers — and said that investigators are seeking “actual indicators of motive and intent.”
A deeper portrait of the gunman’s life is emerging.
Mr. Paddock could be imperious and demanding, expecting other people to wait on him, according to people who knew him. But his youngest brother said he was different with 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,” said Eric Paddock, who lives in Florida. “He went out of his way to be nice to her. This is not something Steve does — go out of his way.”
The gunman was a professional gambler who routinely won and lost thousands of dollars at casinos in Reno and Las Vegas, which often provided him free rooms. “He was a math guy,” Eric Paddock said. “He could tell you off the top of his head what the odds were, down to a tenth of a percent on whatever machine he was playing.”
Stephen Paddock was the eldest of four boys who grew up angry after their father vanished from their lives, but he was the least angry of the group, said another brother, Patrick Paddock. He said that for years, their mother, who struggled to support them on her own, hid from them the fact that their father, a bank robber, had gone to prison, so they had no idea where he was.
“My brother was the most boring one in the family,” he said of Stephen. “He was the least violent one in the family, over a 30-year history, so it’s like, who?”
He said he had not spoken with his oldest brother in 20 years, but would not say why.
Stephen Paddock graduated from California State University, Northridge, a large public institution in the San Fernando Valley of Los Angeles, in 1977. Carmen Ramos Chandler, the university’s director of media relations, said that he had completed a degree in business administration.
His work history was not completely clear. Mr. Paddock worked for the federal government for roughly 10 years, from 1975 to 1985, a spokeswoman for the Office of Personnel Management confirmed.
Investigators unearthed multiple job applications, with Mr. Paddock’s fingerprints on file, as part of records reflecting his employment as a letter carrier for the Postal Service in the mid 1970s; as an Internal Revenue Service agent from 1978 to 1984; and as an auditor focused on defense contracts, a job he held until 1985. He also worked in the 1980s for one of the companies that later combined to form Lockheed Martin, the aerospace contractor.