Paddock's life has remained somewhat of a mystery and most people who have interacted with him said nothing really stood out about him.
A maintenance worker also went to enter the 32 floor shortly after Campos was injured, but Campos "prevented him from receiving any injuries", Lombardo said.
Campos was dispatched to the 32nd floor after a door alarm alerted the security team that Paddock's door was ajar.
It was revealed that the officers were not specialist "Swat" (special weapons and tactics) response, but ordinary Las Vegas police officers responding to police radio chatter about the shooting.
There is no indication anyone other than Paddock fired on the crowd, Sheriff Lombardo said, adding investigators are talking to family members and the girlfriend of the gunman.
But on Monday, the timeline changed.
Officials said Paddock had screwed shut the door with a piece of metal and some screws, but an officer had a pry bar and was able to easily pop it open.
Clark County Undersheriff Kevin McMahill said investigators had "looked at literally everything" and still do not have a clear motive.
"We have been down each and every single one of these paths, trying to determine why, to determine who else may have known of these plans".
Eric Paddock said he came to Las Vegas to retrieve his brother's body in hopes of sending the cremated ashes to their 89-year-old mother in Orlando.More news: Several hurt after auto mounts pavement near London's Natural History Museum
In addition, the officers who raided his hotel room door the night of the shooting gave a harrowing account of a barricaded door they had to bust through and the booby-traps they feared they'd find.
As authorities try to determine as to what led the shooter to carry out the massacre at a concert, the U.S. gun lobby expresses willingness to support a restriction on the rifle accessory that enabled him to fire as if from an automatic weapon.
The previous weekend, Paddock had rented a high-rise condo in a building that overlooked the Life is attractive alternative music festival featuring Chance the Rapper, Muse, Lorde and Blink-182, said Lombardo, who offered no other details about what led Paddock there. But they want to know if anyone knew about his plot beforehand, he said.
Before opening fire, Paddock had smuggled his arsenal into a two-room suite in Mandalay Bay and set up cameras to monitor police as they arrived.
"The investigation is being led by the folks in Las Vegas, and we're in constant conversation with the fusion center here in MA, which is in constant contact with them", Baker said.
McMahill said that investigators have also received more than 1,000 leads from the public, but warned that "rumor and supposition doesn't help".
Federal Bureau of Investigation agents interviewed Marilou Danley, Paddock's girlfriend, hoping she could provide insight into the shooting, but she has said she knew nothing of his plans or potential for such violence.
What otherwise would have been a mundane proceeding offers fresh details about Paddock's life and habits - for the first time - from the killer's own mouth. Paddock's wardrobe did not bespeak of a man of wealth, said the broker, who asked not to be identified discussing the gunman.
Paddock said that in 2006 he "averaged 14 hours a day, 365 days a year" on the video poker machines.
Las Vegas police officer David Newton told CBS News program 60 Minutes on Sunday that he entered the room and saw a note on the shooter's nightstand with numbers that appeared to be created to help his aim.
"A week into this, a lot of people have been numb", said Red Cross spokesman Bill Fortune, who flew in from Colorado to help with the recovery effort.