The 64-year-old high-stakes gambler and retired accountant from Mesquite, Nevada, killed himself as police closed in on his 32nd-floor room at the Mandalay Bay hotel casino. They wonder if he had some sort of mental break at the time that drove him to start making plans for mass murder.
Meanwhile, Southwest Airlines and Allegiant Air say they are offering free flights to family members of people who were killed or injured in the shooting. Police are not aware whether the devices were transmitting - the FBI is investigating their use - but Lombardo told reporters he thinks the shooter might have used them to watch for people approaching his room.
The hail of gunfire stopped when security guards approached Paddock's Mandalay Bay hotel room, McMahill said.
She and Geary Danley reportedly divorced in 2015 and she was living with Paddock in Mesquite, Nevada, 130km from Las Vegas. "That's the one in this one, and we are not there yet", FBI Deputy Director Andrew McCabe said.
Detectives are still trying to determine whether the money was for Danley, who lived with Paddock in Mesquite, or for another goal. An assault rifle rests on a bipod on the floor with a yellow marker reading "19" next it, indicating that the weapon was one of at least 23 police found in the room.
It was not clear when or how Paddock obtained the weapons.
Lombard said his client was cooperating fully with authorities.
However, a senior United States homeland security official speaking on condition of anonymity told Reuters there was "no evidence" Paddock had "mental illness or brain damage".
Federal Bureau of Investigation agents met her plane at Los Angeles International Airport before interviewing her, two USA officials briefed on the case told Reuters.
Mendoza said Paddock would lay into the much smaller Danley when she asked about using his casino card, which had credits from gambling that could be used to pay for things inside the casino.
Still, the sister left open the possibility that Danley could provide information helpful to investigators.
The Vegas massacre is the bloodiest attack in the United States since another lone wolf stormed a gay nightclub in Orlando, Florida past year killing 49.
In a televised address, President Donald Trump described the shooting as an "act of pure evil", but did not make reference to a growing row over Americans' right to bear arms.
The store would not comment on how many guns Paddock bought and said those details could only be shared with authorities as they cooperate with the investigation.