Lombardo said officer's zeroed in on Paddock's location just 12 minutes from the first shot but it was 63 minutes later when they managed to break into his hotel room and confirm that he was dead.
Investigators questioned her about Paddock's weapons purchases, a $100,000 wire transfer to a Philippine bank that they think may have been intended for her, and about whether she saw any changes in his behavior before she left the United States.
A usually quiet neighbourhood in Las Vegas has become overrun with media and the public, trying to get a glimpse of a mass-shooter's former home.
"His bravery was incredible because he remained with our officers, providing them the key pass to access the door and continued to help them clear rooms until our officers demanded he seek medical attention", Lombardo said Thursday. "She was sent away so that she will be not there to interfere with what he's planning".
He never checked in for his reservation, hotel officials say.
Marilou Danley, 62, told Federal Bureau of Investigation officials Paddock, the man behind the worst mass shooting in U.S. history "would lie in bed, just moaning and screaming: "Oh my God" NBC News reports.
The unarmed security guard who approached Paddock's room, Jesus Campos, is being hailed a hero.
As a mother and grandmother "my heart breaks for all who have lost loved ones", she said.
Danley said she was grateful but anxious that the unexpected trip home and the money "was a way of breaking up with me".
Employees at the auto dealership told CBS that Paddock was an "educated consumer" and Danley was "extremely complimentary" of her boyfriend, adding that he had "saved her" from an abusive relationship with her former husband.
Two months before carrying out the attack from the 32nd floor of the Mandalay Bay Hotel, Paddock booked a pair of rooms across the street from Chicago's Grant Park, where the Lollapalooza music festival was held from August 3 to August 6, TMZ reported.