Who is Las Vegas shooter Stephen Paddock? Here's what we know

The man who killed at least 50 people and injured more than 400 at a Las Vegas concert was a retiree with no criminal history in the Nevada county where he lived, police said Monday.

The brother of Stephen Paddock, 64, said he's "completely dumbfounded" by the shooting at a country music concert Sunday night, the deadliest in modern U.S. history. Eric Paddock told the Orlando Sentinel newspaper that he can't understand what happened.

Nevada authorities say they believe Stephen Paddock acted alone, and no motive was yet known.

Paddock owned a single-family home in Sun City Mesquite, a retirement community along the Nevada-Arizona border, Mesquite Police Chief Troy Tanner said.

PHOTOS: Deadly mass shooting in Vegas

He lived there with Marilou Danley, 62. Police say they don't believe she was involved.

Heavily armed police searched the home early Monday, hours after Paddock killed himself in a room at Mandalay Bay Hotel and Casino where police believe he opened fire on a crowd of 22,000 people.

Paddock bought the one-story, three-bedroom home about 80 miles north of Las Vegas in 2015 for about $370,000, according to property records that list him as a single man.

Authorities in Mesquite, Texas, said Paddock had connections to three properties in the Dallas suburb between 2004 and 2012, and listed his home address in 2010 in the 4800 block of Via Ventura.

Mesquite police said Paddock rented a hangar at the Mesquite Metro Airport to store one plane. According to records, he paid his rent on time and did not have any negative interactions with officials.

Police records indicate that authorities did not have any contact with him, according to Mesquite police.

Eric Paddock told reporters Monday in Orlando that his brother Stephen was a multimillionaire who made much of his money investing in real estate. He said Stephen was also an accountant for many years.

He was not aware of his brother having any recent financial difficulties.

Stephen Paddock recently sent a walker by mail to his 90-year-old mother.

The brother says the shooter collected coins when he was a child.

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