Stephen Craig Paddock was a retired accountant who lived on a desert golf course in Mesquite Nevada, with no known history of violence, until he shot dead 58 people in a hail of gunfire from his Las Vegas hotel window.
Paddock's family was in shock after the 64-year-old sowed terror on the Vegas strip in the worst mass shooting in recent US history, which the Islamic State group early Monday claimed was carried out by one of its "soldiers."
Paddock was found dead, apparently of a self-inflicted gunshot wound, when a police SWAT team burst in to his room on the 32nd floor of the Mandalay Hotel.
The gunman, who photographs showed as greying with a trimmed beard and moustache, was a former accountant and a licensed pilot with no criminal record, according to ABC News.
At least eight weapons, including a number of long rifles, were recovered in his hotel room.
Security officials earlier said Paddock appeared to have been working alone, and his brother told US media he had no known religious affiliation.
"Nothing. No religious affiliation, no political affiliation, he just hung out," Eric Paddock told CBS.
The 55-year-old Paddock, who lives in Orlando Florida, told media the family was shocked by the shooting.
"It's like an asteroid just fell on top of our family," he told the Las Vegas Review-Journal. "We have no idea how this happened."
Stephen Paddock also had a hunting license for Alaska, where hunting for big game like elk and bear is popular.
According to publicly available information, he resided in a new golf course development carved into the desert just outside Mesquite, Nevada on the border with Arizona.