Investigators believe Stephen Paddock checked into the Mandalay Bay Resort and Casino days before the worst mass shooting in modern U.S. history. Here’s what we know about the suspected gunman.

MESQUITE, Nev. — The man who carried out the deadliest shooting rampage in modern U.S. history was a 64-year-old retired accountant with a taste for high-stakes poker who had moved to Nevada just a couple of years earlier.

While investigators were still piecing together the attack by Stephen Paddock at a country music concert that left at least 58 dead and 515 wounded, the gunman’s younger brother said the gunman had shown no signs of volatility and was “dumbfounded” as he searched for an explanation for why his brother would carry out such a brutal assault.

“There’s absolutely no way I can even conceive that my brother would shoot a bunch of people he didn’t even know,” Eric Paddock told the USA TODAY Network in an interview. “There’s no rationale. There’s nothing anywhere that said why he did this.”

Clark County Sheriff Joseph Lombardo said officers determined the gunshots were coming from a room on the 32nd floor of Mandalay Bay complex on the Las Vegas Strip. Authorities said it appeared Paddock killed himself.

At least 10 rifles were found in the room; it appeared he had hammered out the windows of the room before shooting.

“Right now, we believe it’s a sole actor, a lone-wolf-type actor,” Lombardo said.

Lombardo added that investigators have yet to determine a possible motive for the rampage. “I can’t get into the mind of a psychopath at this point.”


Investigators believe Paddock used the vantage point to fire on the 22,000-person crowd that gathered for the outdoor concert. He opened fire as the artist Jason Aldean performed.