Fans watch as Charli XCX performs at Lollapalooza in Chicago's Grant Park on Aug 6.
Paddock's longtime girlfriend is originally from the Philippines, and she is believed to have been there when he launched his deadly assault in Las Vegas, killing 59 people and more than 500 others attending a country music festival.
In between, cops arrived on the 31st floor - just below Paddock - at 10:12pm and got to the shooter's 32nd floor at 10:17pm, officials said. "What we know is that Stephen Paddock is a man who spent decades acquiring weapons and ammo and living a secret life, much of which will never be fully understood", he said, adding that investigators were looking into whether something happened in Paddock's life to set off the gun-buying spree.
Paddock is also believed to have been planning to carry out the massacre in Las Vegas a week earlier, having booked rooms at the Ogden overlooking the Life is attractive open-air festival from September 22-24.
The Las Vegas shooter has been named as Stephen Craig Paddock.
Lombardo said the authorities had found no manifesto or anything else to explain Paddock's actions.
Police also mapped out the most detailed timeline yet of Paddock's attack on concertgoers at the Route 91 Harvest Festival.
Investigators have zeroed in on a weapon-buying binge Paddock went on in the year before the attack.
- As NPR's Lauren Hodges and Doreen McCallister report, Paddock's girlfriend, Marilou Danley, who was visiting family in the Philippines at the time of Sunday's shooting, says through her lawyer that the man she described as a "kind, caring, quiet man" gave her no "warning that something frightful like this was going to happen".
House Passes GOP Budget, Setting Stage for Tax Cut Debate
The upper chamber's version is being marked up in committee Thursday and is expected to move to the Senate floor in two weeks. House Republicans are far behind schedule in passing the budget, which is normally approved in the spring.
Federal Bureau of Investigation agents were at Los Angeles airport to escort Australian Marilou Danley, who was in the Philippines at the time of Sunday night's mass shooting - the worst in modern USA history.
"You have to make an assumption that he had some help at some point", Lombardo said.
"This individual is a lone wolf and I don't know how it could have been prevented", he said earlier.
He said the family did not plan to hold a funeral for his brother, who was not religious, saying it could attract unwanted attention.
A representative for Guns & Guitars, Inc. also told ABC News Paddock that was a customer and purchased had firearms legally.
Ms Danley, who has not been arrested, lived with the 64-year-old at his retirement community home in Mesquite, Nevada - and officials searching the property have found a number of weapons.
"We assure though that the BI shall cooperate with any and all of our worldwide counterparts in providing any relevant information that would help their investigation", she said.
"A hostess is a person who caters to their every demand at any moment they want, night or day, be it food, be it a private lap dance with a girl. In this place, money can buy everything".