The Vegas mass shooter

Stephen Craig Paddock, the retired accountant who smuggled an arsenal into a swank Las Vegas hotel and mowed down concert-goers from a 32nd story window, was a high-stakes gambler whose bank-robber father was once on the FBI's most wanted list.

The 64-year-old had a home with his girlfriend in a tranquil golf course retirement community in Mesquite, Nevada, 80 miles northeast of the US gambling capital, and regularly sent cookies to his 90-year-old mother in Florida.

According to his younger brother Eric Paddock, he showed no sign he was poised to commit one of the worst mass murders in American history.

The IS group claimed Paddock was one of its "soldiers," converting to Islam in recent months and carrying out the attack in its name. IS gave him a jihadist nom de guerre, Abu Abdel Bar al-Amriki -- "The American."

But the FBI said they saw "no connection" between Paddock and international terror groups.

"He had nothing to do with any political organization, religious organization, no white supremacists, nothing, as far as I know. And I've only known him for 57 years," Eric Paddock said outside his Orlando, Florida home.

According to Eric, his brother was financially well-off, and had no criminal record. He owned two houses in Mesquite and Reno of Nevada. Neighbors in Mesquite and Reno called him quiet, but mostly keeping to himself.

The brothers grew up in a broken home. Their father, Benjamin Hoskins Paddock, was a violent bank robber jailed in the early 1960s for a series of heists.He escaped prison in 1968, landing on the FBI's "10 most wanted" list. But Eric stressed that his brother gave no signs other than being completely normal, doting on their mother.

"The last time she talked to him, no indication of anything. We're trying to understand what happened," his brother said. "We're lost."