• The authorities found evidence that the gunman, Stephen Paddock, planned to escape after the shooting and survive, Sheriff Joseph Lombardo of the Las Vegas Metropolitan Police Department said at a news conference on Wednesday evening.

• The bureau is trying to reconstruct Mr. Paddock’s actions, including finding and interviewing “everyone and anyone who crossed his path in recent weeks,” Andrew G. McCabe, the deputy director of the F.B.I., said at a cybersecurity conference in Boston.

• The killer “is an individual who was not on our radar or anyone’s radar prior to the event,” Mr. McCabe said in an interview with CNBC outside the conference. “So we really have a challenging bit of detective work to do here, to kind of put the pieces back together after the fact.”

• 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 visited Las Vegas on Wednesday and offered words of support for the victims. “The message that I have is that we have a great country and we are there for you,” he said.

No links to terrorism have been found, the F.B.I. says.

Aaron Rouse, the F.B.I. special agent in charge in Las Vegas, said there was “no evidence to indicate terrorism, but this is an ongoing investigation.” Mr. Rouse said at a news conference on Wednesday evening that agents were pursuing several theories about what may have motivated Mr. Paddock.

Sheriff Lombardo seemed skeptical that Mr. Paddock moved the guns into his hotel suite by himself. More than 20 guns and thousands of rounds of ammunition were recovered in the suite. They had been brought into the Mandalay Bay Resort and Casino in at least 10 suitcases, the authorities said.

“It was troublesome that he was able to move this much gear into the hotel unassisted,” the sheriff said.

A leaked photograph of the gunman’s hotel suite appears to show a piece of paper on a table. Asked about the note, the sheriff said, “It was not a suicide note.”

Law enforcement officials said on Tuesday that ammonium nitrate had been recovered from Mr. Paddock’s car at the Mandalay Bay. On Wednesday, Sheriff Lombardo said the car also contained other explosives: 50 pounds of tannerite, a nonflammable exploding target used for practice, and 1,600 rounds of ammunition.

The gunman’s girlfriend said she didn’t know he was ‘planning violence.’

“I knew Stephen Paddock as a kind, caring, quiet man. I loved him and hoped for a quiet future together with him,” Ms. Danley said in her statement. “It never occurred to me in any way whatsoever that he was planning violence against anyone.”

Ms. Danley said she was grateful to Mr. Paddock for the trip to the Philippines, her native country, to visit family, but when he wired her money, “which he said was for me to buy a house for me and my family,” she feared that it was his “way of breaking up with me.”

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.

Image Marilou Danley, the girlfriend of Stephen Paddock, the gunman who carried out the Las Vegas attack. Credit... Las Vegas Metropolitan Police Department, via Reuters

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.

The president met with victims of the attack.

Mr. Trump spent four hours in Las Vegas on Wednesday, including paying tribute to the professionalism of the doctors who treated the Las Vegas shooting victims. He said that meeting with the patients at one hospital made him “proud to be an American.”

The president said he met with some “absolutely terribly wounded” patients and hailed their bravery during the horrific attack Sunday night. He said many of those he met with were wounded as they sought to help others amid the hail of bullets from the shooter in a nearby hotel.

In brief remarks to reporters before meeting with law enforcement officials in Las Vegas, Mr. Trump said, “I think the only message I can say is that we are with you 100 percent.” Read more about his visit from our reporters.

A total of 489 people were injured in the attack, and 317 have been released from hospitals, Sheriff Lombardo said Wednesday evening.

Body camera footage captured the officers’ response.