Pictures of the hotel room and weapons stashed by Stephen Paddock have been revealed, following audio from police scanners which detail what happened in the 72 minutes it took to find him.
In footage obtained by Bild, an assault rifle resting on a bipod is seen on the floor through the breached door, which is crisscrossed by yellow crime-scene tape.
It has also emerged Paddock set up a camera inside the room, as well as other surveillance in the hallway to alert him as police closed in on him, according to reports.
And in images obtained by Boston 25, two other assault rifles Paddock used to massacre 59 people are seen lying on the floor in the corner suite, amid dozens of spent cartridges.
TV station reporter Jacqui Heinrich tweeted the photographs, which also show a hammer that Paddock, 64, presumably used to smash the windows of his suite to set up his sniper's perch.
Police believe Paddock had up to 10 suitcases stored in the suite and may have ferried up weapons and ammunition over several trips. It's believed he used the bipod to set up a "sniper's perch" from which to spray the crowd with bullets from two different vantage points.
Pictures from inside the suite show a DDM4 rifle with rounds of ammunition.
Paddock is reported to have had four of the high-powered DDM4 rifles with a muzzle-flash suppressor which could make it more difficult to tell where the weapon is being fired from.
He also had a Colt AR-15 similar to that used by San Bernardino terrorist Omar Mateen, and three FN-15 rifles with at least one AK47.
Paddock is also said to have used "bump stocks" and larger magazines than usual to fire off more rounds than would normally be possible. A search of his home revealed another 19 guns and a fertiliser used as an explosive found in his car.
The first look inside the grisly crime scene comes after police audio revealed exactly what happened in the 72 minutes following first reports of a "code red" that "sounds like an automatic firearm".
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"I see the shots coming from Mandalay Bay halfway up," says one policeman just after 10:08pm. However this is quickly confused with other misinformation about reports of an "active shooter inside the fairgrounds".
Unidentified police, dispatchers and members of a SWAT team can be heard scrambling to work out the source of the shooting while dealing with reports of casualties. After five minutes an officer said: "I'm inside the Mandalay Bay on the 31st floor. I can hear the automatic coming from one floor ahead, one floor above us."
On the ground, a dispatcher tells police to avoid becoming sitting ducks by travelling down Las Vegas Boulevard as victim reports flood in.
"We can't worry about victims, we need to stop the shooter before we have more victims," an officer said. "Anyone have eyes on the shooter?"
Moments later, another agrees: "We can't worry about the wounded and whether they're hurt or not, we've got to contain the threat," he said.
The officers tell staff to "shut down their elevators" and block stairwells to stop the shooter escaping. A strike team is formed, while one officer calmly insists "I'm on the 32nd floor the room is going to be 135."
Retired Las Vegas lieutenant Randy Sutton said later the smoke alarm triggered by Paddock's incessant shots was what ultimately gave away his position. He said Paddock used the high vantage point and massive ammunition stocks to "rain down hell" on the concertgoers.
At the time, police also flooded the 29th floor following reports of a shooting there which turn out to be false. On level 32, an officer said Paddock "shot down the hallway and hit a security guard."
On the ground, the dispatcher advises police to lock their cars as "citizens are trying to grab shotguns."
"I need some more units here I'm being overtaken by citizens trying to take patrol cars," one officer said. Another advises against travelling to a certain part of the festival ground.
"The more officers that come over here, the more that will be pinned down," he said.
After 39 minutes the SWAT team is nearly in place but the floor still contains innocent hotel guests who have not yet been evacuated.
On the ground, an officer said: "I had a civilian take a patrol car" and teams warn of "booby traps" and a "blue-on-blue" in the ambush - referring to an accidental shooting of officers.
Around 1 hour and 12 minutes after the first reports, a SWAT team member says: "We need to pop this and see if get any type of response from this guy to see if he's in here or if he has moved out somewhere else."
"Breach! Breach! Breach!" can be heard along with an explosive sound and the words "one suspect down inside the room."
The audio provides a chilling insight into the reality for first responders into the most deadly shooting the US has seen in recent history.
It also shows the mass of confusion police were forced to deal with, including reports of separate shootings at the Tropicana, Caesars Palace and Bellagio hotels that turned to be false.
Las Vegas police are still searching for a motive as to what caused the retired accountant to kill 59 others and injure more than 500 before taking his own life.
At his home, police found 19 more guns, explosives and thousands of rounds of ammunition as well as ammonium nitrate, a fertiliser that can be turned into explosives, in his car, authorities said.
The high-stakes gambler has also been revealed as the son of a notorious fugitive who lived in a Nevada retirement village with his girlfriend, Marilou Danley, 62, who was an Australian citizen.
Paddock had no previous criminal record and former FBI hostage negotiator Clint Van Zandt said there are no clues as to what triggered the massacre.
"My challenge is, I don't see any of the classic indicators, so far, that would suggest, 'OK, he's on the road either to suicide or homicide or both," Van Zandt told AP.
"He knew what he wanted to do. He knew how he was going to do it, and it doesn't seem like he had any kind of escape plan at all."