Stephen Paddock was the gunman behind the deadly attack on the Las Vegas Strip which saw at least 59 people killed and 525 injured.
The 64-year-old opened fire from the 32nd floor of the Mandalay Bay hotel onto the 22,000-strong crowd at a country music festival.
Who was the man behind the worst mass shooting in modern American history?
Police said 23 guns were found in Paddock’s hotel room and another 19 firearms, some explosives and thousands of rounds of ammunition were found at his home, located 145 km northeast of Las Vegas. Twelve of the his firearms had been modified into machine-gun-like weapons with so-called “bump-stocks”.
Law enforcement authorities have found ammonium nitrate in the shooter’s car. The compound is a fertiliser but can also be used in the making of explosives.
Paddock’s firearms have been associated with the Guns & Guitars shop in Mesquite, where he was from.
Chris Sullivan, the owner of the gun shop, is cooperating with investigators and has confirmed the shooter was a customer. Sullivan said Paddock cleared “all necessary background checks and procedures”.
“He never gave any indication or reason to believe he was unstable or unfit at any time,” he said.
Adam Le Ferve, the former brother-in-law of Paddock’s girlfriend, recalled to NBC a visit to the shooter’s house in which he showed off his “gun room.” Paddock reportedly told Le Ferve he was adamantly opposed to gun controls.
Paddock was a licensed pilot, who owned two planes. He also had a hunting license from Alaska.
Le Ferve said Paddock claimed to go hunting a couple of times a year, and was not a fan of country music.
Senior law enforcement officials and a casino executive say that Paddock had gambled significant amounts of money at casinos in Las Vegas in the weeks before October 2.
There were 16 currency transaction reports (CTRs) filed on Paddock over the last few weeks, according to NBC News.
Casinos have to file CTRs when there has been transactions of more than $10,000 (€8,520), either in or out of the account.
An executive and official cited several occasions where Paddock gambled amounts over $20,000 (€17,040) and $30,000 (€25,560) in a single day.
He was also a frequent player. He had the highest ‘seven stars’ status at Nevada gaming firm Caesars Entertainment, meaning he got privileges such as free rooms, upgrades and player credits.
Le Ferve told NBC that Paddock spoke a lot about his success with gambling, and approached it like a business.
“He told me you’ve got to be strategic, you’ve got to be logical,” he said.
According to Le Ferve, Paddock gambled from a pool of $1.5 million and used an algorithm for placing bets.
The shooter reportedly said his return on gambling was greater than if he had invested in stocks.
“His investments, his gambling were done with military precision. Everything he did was planned out to the end,” said Le Ferve.
Paddock has moved between 27 residences in California, Texas and Nevada.
Public records show he was employed by a predecessor company of Lockheed Martin between 1985 and 1988 as an “internal auditor”.