MSNBC reported on Friday a mobile phone charger that did not match Paddock's phone was found in his Mandalay Bay suite and it appears the keycard for his room was used to open the door when his vehicle had left the casino auto park.
Authorities are "very confident" there was just one shooter in the suite on the 32nd floor of the Mandalay Bay Resort hotel but "continue to investigate whether anybody else may have known about this incident before he carried it out".
He says Stephen Paddock planned to survive and escape but didn't say how.
Authorities have said they plan to return the belongings to people in the next week.
Paddock booked a room that overlooked Chicago's Lollapalooza, the perennial music festival that draws over 400,000 people over four days in early August, local media, as well as the Associated Press have reported.
According to Las Vegas's sheriff, accused shooter Stehpen Paddock also rented a room near downtown Las Vegas last month at the same time as an alternative music festival nearby.
"She said he would lie in bed, just moaning and screaming, 'Oh, my God, '" said a former Federal Bureau of Investigation official briefed on the matter, NBC News reported.
"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".
Minutes after the shooting began, a hotel security guard showed up outside his suite and Paddock shot him in the leg.
"You gotta make the assumption he had to have some help at some point", said Lombardo.
Police are looking into whether Paddock hired a prostitute before the massacre.
Their sources say that neither Paddock nor his girlfriend had previously stayed at the hotel.
Investigators found 23 guns inside Paddock's hotel room and 12 so-called "bump stock" devices that can enable a rifle to fire continuously.