Stephen Paddock had a gun room at home because he didn't want firearms "falling into the hands of the wrong people", a former friend of the US mass murderer says.
Australian businessman Adam Le Fevre has told the Nine Network he was welcomed into Paddock's home while going out with Liza Werner, the sister of Paddock's girlfriend Marilou Danley.
"He (Paddock) said, well most people in the US have firearms and they need to be protected and, of course, you don't want firearms falling into the hands of the wrong people," Mr Le Fevre said on Friday.
Mr Le Fevre holidayed three times with 64-year-old Paddock, who shot dead 58 people in 10 minutes from the 32nd floor of the Mandalay Bay hotel in Las Vegas on Sunday night.
Paddock killed himself before police stormed his hotel room.
"He was very strict and very firm on the fact that it is a right, it is a capacity and it's the freedom of every American resident ... to own a gun and use it as seen fit where need be and that law should never be changed," Mr Le Fevre said.
He believes Ms Danley, who was in the Philippines at the time of the shooting, had no inkling of Paddock's murderous plan.
"I would believe that, absolutely, without any doubt, that Marilou would have had no knowledge of what Stephen Paddock was able to plan," Mr Le Fevre said.
He said Marilou seemed nervous around Paddock who would talk to her in a condescending way.
"I saw him talk to her abruptly and Liza and I away from them questioned whether everything was alright with them," he said.
Ms Danley, who lived in Queensland in the 1980s, returned to Las Vegas from the Philippines on Wednesday to be questioned by investigators.