The motive behind the deadliest mass shooting in modern U.S. history remained a mystery Monday as police sought to learn more about the apparent "lone wolf" gunman who opened fire on thousands of concertgoers from the 32nd floor of a Las Vegas hotel.
At least 59 people were killed and hundreds more were injured in the shooting, which happened during a performance by country music star Jason Aldean Sunday night at the Route 91 Harvest Festival. The gunman hammered out a window at the Mandalay Bay Hotel and Casino and began firing with a cache of weapons . Authorities who stormed the suspect's room found that he had killed himself.
Here are some things happening in response to the tragedy:
Authorities are discounting the possibility that international terror organizations were involved in the shooting, despite a claim of responsibility by the Islamic State group.
The suspected gunman, Stephen Craig Paddock, a 64-year-old retiree from Mesquite, Nevada, wasn't on the radar of law enforcement. They think he acted alone but want to talk with his 62-year-old roommate.
"I can't get into the mind of a psychopath at this point," Sheriff Joseph Lombardo said.
Two officials familiar with the investigation say authorities found at least 17 guns in Paddock's hotel room.
The sheriff's department is leading the investigation, and Attorney General Jeff Sessions ordered support from the FBI and other federal agencies.
At least 527 people were injured in the attack, along with the 59 confirmed dead.
Among the confirmed fatalities was Sonny Melton, a registered nurse. His wife, Dr. Heather Melton, an orthopedic surgeon who was with him when shots were fire, survived.
Heather Melton told WZTV in Nashville that her husband "saved my life and lost his." She says her husband was the most kind-hearted, loving man she ever met.
Others slain include commercial fisherman Adrian Murfitt, 35, of Anchorage, Alaska; Lisa Romero, a high school secretary from Gallup, New Mexico; Rachael Parker, a records technician with the Manhattan Beach Police Department; and mechanics' apprentice Jordan McIldoon, 23, of Maple Ridge, British Columbia.
Paddock's brother, Eric Paddock, who lives in Florida, says his multimillionaire brother was a big spender at casinos and often received free meals and rooms there.
Eric Paddock also described his brother as different than other people: "He was a guy who had money. He went on cruises and gambled."
Stephen Craig Paddock was living in Mesquite, Nevada, and authorities say he previously lived in the Dallas suburb of Mesquite, Texas, from 2004 to 2012, and possibly longer. Lt. Brian Parish says property records show Paddock owned at least three rental properties.
Officers searched the Nevada home on Monday, and authorities there and in Texas indicated there wasn't law enforcement contact with him. However, his father, Benjamin Hoskins Paddock, was a notorious bank robber who wound up on the FBI's most wanted list after escaping from prison in 1968.
LAS VEGAS SECURITY
The mass shooting underscored how easy it can be to bring weapons and other contraband into hotels. Although it wasn't immediately clear how he got the weapons and ammo to his room, security experts say he easily could have hid them in suitcases, golf bags or other innocuous containers.
"Based on the amount of ammunition that this guy threw down there, he took more than one trip or he had a luggage cart that was carrying all this stuff," said Angela Hrdlicka, a former Secret Service agent who is now a private security consultant for Major League Baseball parks and other professional sports.
President Donald Trump says he plans to visit Las Vegas on Wednesday to meet with first-responders. He says the visit will come "on a very, very sad moment for me ... for everybody no matter where you are, no matter what your thought process."
Trump called the shooting an "act of pure evil" during an address from the White House.
The president and first lady Melania Trump were leading a moment of silence Monday afternoon at the White House South Lawn to honor the victims. He also spoke by phone with British Prime Minister Theresa May about the shooting.
Meanwhile, Democrats renewed their call Monday for new gun safety legislation. There was no indication that would get much traction, although the fata of Republican legislation backed by the National Rifle Association remained in limbo.
COUNTRY MUSIC REACTION
Stars from the world of country music sent out their condolences to the victims of the tragedy.
Luke Combs, who performed earlier in the night, said on Instagram: "I can't help but hurt for all the people who weren't as fortunate and the pain their loved ones must feel."
Carrie Underwood posted on Twitter : "Woke up to such horrible news. We are praying for the victims and their families. May the Lord bring some comfort to them."
"Stilled and speechless," Keith Urban tweeted. "Our hearts and prayers are with everyone involved and affected."
UNITED IN TRAGEDY
Among the people showing empathy for the Las Vegas victims were family members who lost loved ones in the 2012 shooting at Sandy Hook Elementary school.
Nelba Marquez-Greene, whose 6-year-old daughter Ana Grace was among the Sandy Hook victims, sent a series of tweets about the shooting and the conversations surrounding gun violence, including race and public outrage.
"As a mom who had to bury a child- I could care less about perp color," wrote Marquez-Greene. "But how come we never talk about angry White men w/guns? How come we only want to talk when it fits our own narrative? Please. Help mothers keep children safe from gunviolence."
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