Police have identified Stephen Paddock as the gunman who opened fire on concertgoers from a hotel room in Las Vegas, killing at least 58 people and leaving 515 wounded in the deadliest mass shooting in U.S. history.

Paddock, 64, began shooting from the window of his room on the 32nd floor of the Mandalay Bay Resort and Casino just after 10 p.m. local time Sunday evening, police said. A SWAT team found Paddock dead in his hotel room and suspect he killed himself.

Police said Paddock had "at least 10 rifles" in the room. He had been staying in the room since Sept. 28 and was traveling with a female companion named Marilou Danley. Police said they had spoken to Danley, who was overseas at the time of the shooting.

FBI Special Agent in Charge Aaron Rouse said in a press conference Monday morning that the bureau had found "no connection with an international terrorist group."

Paddock had been living in a retirement community in Mesquite, Nevada, about 75 miles northeast of Las Vegas, according to the Mesquite Police Department. He had no criminal record beyond a routine citation several years ago that was handled in court.

Eric Paddock, the gunman's brother, spoke to reporters outside his home Monday morning. Eric Paddock said he is "horrified" and "dumbfounded" by his brother's actions. "No religious affiliation. No political affiliation. He just hung out," Eric Paddock said.

Stephen Paddock in undated image. (Via CBS)

"He had a couple of guns but they were all handguns, legal," Eric Paddock said. "He might have had one long gun, but he had them in a safe."

President Trump called the shooting "an act of pure evil" in remarks Monday morning. He hailed first responders and said that the FBI and Department of Homeland Security are working with local officials in the investigation.

Investigators are still trying to determine Paddock's motive. The Islamic State of Iraq and Syria (ISIS) claimed responsibility for the shooting but offered no proof. U.S. officials tell CBS News there are no signs that Paddock had ties to radical Islamic groups or showed signs of being radicalized. Police obtained a search warrant for his home in Mesquite and are securing the site, a law enforcement source said.

Records show Paddock moved to Mesquite in June 2016. He had previously lived in Reno, Nevada, from 2012 to December 2016, and was listed at an address in Melbourne, Florida, from 2013 to 2015. Paddock moved between Texas and California from the late 1990s to the early 2000s.

Paddock worked for a "predecessor company" of defense contractor Lockheed Martin from 1985 to 1988, the company said. Lockheed said it was cooperating authorities to provide details of his employment. The company declined to say what position Paddock held.

Court records show Paddock sued the Cosmopolitan Hotel and Resorts on the Las Vegas strip in 2012, alleging he suffered substantial injuries when he slipped and fell in the hotel. The case was dismissed by both parties, indicating they had reached a settlement.

Paddock was a licensed hunter and had a license to fly a small plane, records show.

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