The retired accountant who opened fire on country music concertgoers in Las Vegas had an arsenal of 23 guns in the hotel room he used as a sniper's perch. Authorities found more guns, ammunition and explosives in a search of his Nevada home.
The rampage by Stephen Craig Paddock killed at least 59 people and injured 527, some from gunfire and some from a chaotic escape.
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More about the deadliest mass shooting in recent U.S. history:
The investigation
Some of the guns found in Paddock's room on the 32nd floor of the Mandalay Bay Hotel casino had scopes on them. He used 10 suitcases to tote them all to his room.
Also found were two "bump stocks" that can be used to modify guns and make them fire as if they were fully automatic, according to two U.S. officials briefed by law enforcement who spoke on condition of anonymity because the investigation was still unfolding.
A search of Paddock's home in a retirement community in Mesquite, Nevada, turned up 19 more guns, explosives and thousands of rounds of ammunition. Several pounds of ammonium nitrate, a fertilizer that can be turned into explosives, were found in Paddock's car.
The victims
Among the confirmed fatalities was Christopher Roybal — described as jovial and fun-loving, despite experiencing intense combat during in four Middle East combat tours.
Roybal, 28, worked at Crunch Fitness in Corona and Riverside, California, before he moved at the beginning of the year to help open franchises in Colorado Springs.
"He was the guy who if your car broke down in the middle of the night, you could call him and he would come help you," said David Harman, who founded a company that owns the Colorado gym where Roybal worked. "He is that guy who would find solutions, not report on problems."
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Others slain include a Tennessee nurse, an Alaska commercial fisherman, a high school secretary from New Mexico, a Canadian mechanic's apprentice from British Columbia and a California elementary school office manager.
The gunman
Paddock, 64, killed himself in his hotel room before authorities arrived. Law enforcement and family members have not been able to explain what motivated the multimillionaire who made much of his money from real estate deals to inflict so much carnage.
On the surface, Paddock didn't seem like a typical mass murderer, said Clint Van Zandt, a former FBI hostage negotiator and supervisor in the bureau's behavioral science unit. Paddock is much older than the typical shooter and was not known to be suffering from mental illness.
Public records offered no hint of financial distress or criminal history, though multiple people who knew him said he was a big gambler.
"No affiliation, no religion, no politics. He never cared about any of that stuff," said his brother, Eric Paddock. "He was a guy who had money. He went on cruises and gambled."
Heroic actions
Concertgoer Anna Kupchyan credits a man she knows only as Zach for saving her life and about nine others when he herded them into an outdoor trailer serving as a restroom.
Kupchyan, a 27-year-old law student from Los Angeles, said bullets were raining down on the crowd as she and a horde of others began running in search of a way out of the outdoor venue.
The man, Zach, opened a door and ordered people inside and then joined them and shut the door, Kupchyan said.
President speaks out
President Donald Trump called Paddock a "very, very sick individual."
Trump spoke to reporters Tuesday as he departed for a trip to hurricane-ravaged Puerto Rico. He called the gunman "demented" and said "we're looking into him very seriously."
Trump praised Las Vegas police, saying they had done an "incredible job."
Asked about gun laws, the president said "we'll be talking about gun laws as time goes by."
