He was 64 years old and, to those who knew him, showed no signs of mental illness, extreme political views or an unhealthy interest in guns. He liked to gamble, and had bounced around over the years, living in Southern California, Texas and Nevada. But he seemed to have plenty of money, and had held steady jobs as a mail carrier, accountant, auditor and apartment manager.
In an era when social media invites full-throated expression of even the most minor annoyance, Paddock gave away no hint of whatever it was that drove him to commit mass murder on the Las Vegas Strip, killing 59 people in an assault on a country music festival late Sunday night.
"We are completely dumbfounded," said a younger brother, Eric Paddock, who broke into tears in front of his suburban Orlando, Fla., home. "We can't understand what happened."
"He was always normal," said Donald Judy, a former next-door neighbor who said he was struggling to reconcile the friendly conversations about real estate and family with carnage carried out from a hotel room on the 32nd floor of the Mandalay Bay Resort and Casino.
Almost every week, Paddock and his girlfriend, Marilou Danley, would go to Peggy Sue's bar and diner in Mesquite, where they would have a few drinks and she would sing karaoke, other patrons and the bartender said.
"She really could sing – great set of pipes," Bob Hemley said. "Him? He didn't affect me. Didn't stand out."
Everyone seated at the U-shaped bar Monday evening remembered Danley in particular. Bartender Monique Ortega said that when she learned Paddock was the shooter, she called her boss immediately.
"Now [that] I know that it was him, he seemed kind of creepy," she said.
Paddock, described by the local sheriff as a "lone wolf" attacker, killed himself inside the luxury suite at the Mandalay as SWAT officers closed in. On Monday, authorities searched his light-orange, single-story stucco house in Mesquite and a second home in northern Nevada and questioned relatives and associates but acknowledged that they had uncovered no explanation yet.
Paddock gambled frequently, and two law enforcement sources said he had made chip purchases in Nevada casinos in the last year that were in excess of $10,000 a day, the amount required to be reported to the government.
But relatives and acquaintances said he was a successful real estate investor who showed no sign of financial problems.
Asked if authorities had a working motive at a news conference Monday afternoon, Clark County Sheriff Joe Lombardo replied, "No, we don't."
Investigators have all but dismissed a claim by Islamic State that Paddock was a recent convert to Islam acting at the group's direction. Law enforcement authorities seized computer hard drives from Paddocks' Mesquite home and are examining dozens of weapons taken from the hotel suite and the home along with explosive material found in his vehicle and residence.
U.S. Rep. Ruben Kihuen (D-Nev.), who received a briefing from the multiagency anti-terrorism center, said no new clues have emerged so far.
"Law enforcement were looking through his computer. They couldn't find a motive. As of a couple of hours ago, there was no motive. That's all we know," he said late Monday afternoon.
Before Monday, Paddock had been a nonentity to local police. "We didn't have prior run-ins with him, we didn't have any traffic stops, we didn't have any arrests of any kind," Mesquite Police Officer Quinn Averett said. "It's a newer home, a newer subdivision, a nice clean home, nothing out of the ordinary."
Agents hope they may learn more from Danley, 62. Police were initially searching for her in Nevada as a person of interest in the shooting, but later learned she was out of the country.
Lombardo said she was currently in Tokyo, and investigators are arranging an interview.
Paddock grew up in Arizona, the son of a notorious bank robber. Benjamin Hoskins Paddock, who went by the aliases "Chromedome" and "Big Daddy," robbed a bank in Tucson in 1960, when Stephen was 7 years old.
When authorities cornered the elder Paddock in Las Vegas, he attempted to run down an FBI agent with his car, according to press clippings. He escaped from federal prison in Texas, where he was serving a 20-year sentence, on New Year's Eve 1968. Wanted posters described him as "psychotic," "armed and very dangerous," and an avid bridge player and gambler. He was removed from the list in 1977, according to the FBI website.
He was captured the following year in Oregon and died in 1998.
Stephen Paddock, who was divorced twice, spent much of his adult life in the Los Angeles area. He and his wives lived or owned property in Panorama City, Cerritos, North Hollywood and other areas from the 1970s to early 2000s.
Paddock's former brother-in-law, Scott Brunoehler, recalled the gunman in the 1970s and 1980s as a smart, fun-loving person who enjoyed entertaining on his boat at Castaic Lake and Buena Vista Lake in Kern County.
"He seemed like a normal, good guy. I don't remember anything bad back then at all," said Brunoehler, whose sister, Sharon, married Paddock in 1977. "I'm still in shock."
Paddock listed his occupation as postal carrier at the time of their marriage. He worked for a predecessor to
He also owned rental properties across the country. In Los Angeles, Paddock co-owned two run-down apartment buildings in a working-class neighborhood of Hawthorne.
For nearly a decade, he owned an apartment complex in the Dallas suburb of Mesquite. Tenant Richard Gehring said Paddock improved the Texas property by checking applicants' credit and quickly evicting those who didn't pay.
"Some of the rougher people left," said Gehring, a roadway engineer.
As he watched television coverage Monday, Gehring said it seemed impossible that the gunman was his mild mannered landlord.
"He was just a nice guy, and that was it," Gehring said. "There's nothing really that sets him out from anybody else."
Paddock sold the complex in 2012.
Paddock had lived near his mother and brother in Florida for several years but decided to move to Nevada a few years ago to escape the humidity and play high-level poker, Eric Paddock said.
Donald Judy's wife, Sharon, who lived next door to Paddock in Florida, said he described himself as a world traveler and "professional gambler by trade" and said he once showed her a picture of himself winning a $20,000 slot-machine jackpot.
"He was friendly all the time," she said.
Paddock liked to gamble in Strip hotels. He sued the swanky Cosmopolitan in 2012, claiming he fell and was injured on the hotel property and sustained "substantial injuries." He sought damages of more than $10,000. The suit was dismissed by agreement between the parties in 2014, according to the Las Vegas Review Journal. His attorney declined to comment.
Speaking outside his home in Waterford Lakes, Eric Paddock said his brother was never violent and had no history of mental illness or known ties to extremist groups. His brother had some guns but never a machine gun or an automatic weapon, Eric Paddock said.
"He's never even drawn his gun before," he said. "He's just a guy."
Authorities said they found a total of 42 guns in the hotel room and Paddock's house. At least one had been modified to make it tantamount to an automatic weapon.
Paddock and Danley moved to a house on Babbling Brook Court in a new 55-plus community called Sunset Mesquite in 2015. Residents of their subdivision had little information for police, according to Lombardo, the sheriff.
"He was reclusive," Lombardo said.
One neighbor, who declined to give his name, described Paddock to a reporter as "a real loner."
"If he saw you a few time he'd finally say, 'hi,'" the man said.
A sign posted on the front door of a next-door neighbor read, "We do not have anything to provide relating to the actions of our neighbor or insight into his behavior. We did not know him."
Vives reported from Mesquite, Nev., and Serna and Ryan from Los Angeles. Times staff writers David Montero in Mesquite; Richard Winton, Adam Elmahrek, Joel Rubin, Victoria Kim, Brittny Mejia and Paul Pringle in Los Angeles; Joseph Tanfani in Washington; and Orlando Sentinel reporters
8:35 p.m.: This article has been updated throughout with latest figures, background and details.
11:45 a.m.: Updated with information about Texas ties and Lockheed statement.