Stephen Paddock: Police search for motive of killer behind deadliest mass shooting in US history

The man who carried out the deadliest mass shooting in modern US history was a “lone wolf” – a divorced accountant who lived in a retirement community outside of Las Vegas and whose murderous actions have left both police and the people who knew him scrambling to find a motive.

Officials said 64-year-old Stephen Paddock shot himself some time before a police Swat team stormed his room on the 32nd floor of the Mandalay Bay hotel-casino, from where he had opened fire on a country music festival where 22,000 people were present, armed with more than 10 rifles and two tripods.

Officials believe he had altered those legally purchased weapons to operate on automatic, before he began his deadly spree at around 10.08pm on Sunday.

Paddock had checked into the hotel on Las Vegas’s celebrated Strip three days earlier, having driven from his home in the city of Mesquite, 80 miles to the north-east, where he lived with his girlfriend.

Police had initially thought that the woman, Marilou Danley, was somehow involved in the attack, but detectives now believe Paddock used her ID to check into the room. She is currently outside of the US, in the Philippines, and police have spoken to her.

As police began to put together a profile of Paddock – he had moved from Florida two years ago, he had bought the modest property in 2015, previously he had lived in Texas, California, and other places in the West, he enjoyed $100-a-hand poker – they said they were struggling to answer the most pressing question: what drove him to perpetrate such a deadly, calculated act.

“Right now, we believe it’s a sole actor, a lone-wolf-type actor,” Las Vegas sheriff Joseph Lombardo told reporters, saying he was a “psychopath”.

“We have no idea what his belief system was. Right now, we believe he was the sole aggressor.”

The city’s mayor, Carolyn Goodman, called him a “crazed lunatic full of hate”, but officials also said background checks had failed to show up any “derogatory” information and they were quick to dismiss any links to international terror groups, seemingly debunking a claim of responsibility by Isis.

Paddock’s brother could similarly offer few insights. Eric Paddock told Reuters the family was stunned by the news and that his brother had not been an “avid gun guy”.

“We have no idea. We’re horrified. We’re bewildered and our condolences go out to the victims,” Mr Paddock said. “We have no idea in the world.”

He said he had helped his brother move to Nevada two years ago in order for him to be able to play more poker and video poker. The two were last in touch a few weeks ago, when they exchanged text messages about power outages after Hurricane Irma hit Florida.

The Orlando Sentinel said a former neighbour, Sharon Judy of Viera, Florida, said Paddock was a friendly man who had described himself as a professional gambler. Once he had showed Ms Judy a picture of himself winning a $20,000 slot-machine jackpot. “He was friendly all the time,” she said.

As part of their search for clues, police are searching Paddock’s home in Mesquite, where they discovered some guns and ammunition, though not in large numbers. Property records show the home is located in a retirement community, Sun City Mesquite, a development of about 1400 homes. The community includes an 18-hole golf course, indoor and outdoor swimming pools and a recreation centre. Reports said residents must be at least 55 years old, and no children are allowed.

Police said officers had located a Hyundai Tucson and a Chrysler Pacifica Touring, both with Nevada license plates, which were registered to the dead suspect.

“We don’t have a lot on Mr Paddock. He does live here in our city. We have not had any law enforcement contact with him in the past,” Quinn Averett, a spokesman for the Mesquite police department, said at a press briefing.

“It’s a nice, clean home and nothing out of the ordinary.”

One detail of Paddock’s profile that leapt out in media reports was revealed by his brother – namely that his father was a well-known bank robber and at one point was on the FBI’s 10 most wanted list. Their father, Patrick Paddock, died a few years ago.

CNN said Paddock had bought multiple firearms in the past, several of them purchased in California. Yet it does not appear that those weapons were among the ones used in the Las Vegas massacre, it said.

The network said officials suspect the weapons that were used – among the weapons found in Paddock’s room were a .223 calibre and a .308 calibre rifle – were legally purchased guns that were altered to fire automatically. They would help explain the high number of people both killed and injured.