According to the reports, the gunman, Stephen Paddock set up a camera in his hotel room to film his shooting rampage and another camera in the corridor of the hotel to look out for approaching police officers.
A video footage shows a camera set up on a tripod pointed out the window with a view of both the shooter and the crowd of concert goers below.
In order to break the window glass before the shooting, he used a hammer-like tool.
According to the police, he had an arsenal of 23 guns in his Mandalay Bay Resort and Casino suite. The firearms included four DDM4 rifles, three FN-15 rifles, one AK-47 rifle, and one AR-15 rifle. At least one of the rifles was fully automatic, while another two were equipped with devices that allowed for fully automatic power. Police also found several handguns in the room.
Paddock fired repeatedly over the course of 72 minutes at a rate of up to 800 rounds per minute.
Even the law enforcement officials puzzled on Tuesday, Oct. 3, about the fact what motivated Paddock, a retiree with no criminal record, to assemble an arsenal in a high-rise Las Vegas hotel and rain gunfire onto an outdoor concert.
The Sunday night shooting spree is one of the deadliest in modern U.S. history, by killing himself. He left an arsenal of 42 guns but no clear clues as to why he staged the attack on a crowd of 20,000 from a 32nd-floor window of the Mandalay Bay hotel. More than 500 people were injured, some trampled.
While investigating federal, state, and local investigators have found no evidence that Paddock, 64, had even incidental contacts with foreign or domestic extremist groups, and reviews of his history show no underlying pattern of lawbreaking or hate speech, a senior U.S. homeland security official said on Tuesday.
“We cannot even rule out mental illness or some form of brain damage, although there’s no evidence of that, either,” the official said, speaking on the condition of anonymity to discuss the probe.
On Tuesday, US President Donald Trump told reporters that Paddock had been “a sick man, a demented man.” He declined to answer a question about whether he considered the attack an act of domestic terrorism.
U.S. officials discounted a claim of responsibility by ISIS and said they believed Paddock acted alone.
Although police said they had no other suspects, Clark County Sheriff Joseph Lombardo said investigators wanted to talk with Paddock’s girlfriend and live-in companion, Marilou Danley, who he said was traveling abroad in Tokyo.
The closest Paddock ever appeared to have come to a brush with the law was a traffic infraction, authorities said.
Las Vegas Police said they would next provide an update on the investigation at 1 p.m. PT (1900 GMT).
Paddock seemed atypical of the troubled, angry young men who experts said have come to embody the mass-shooter profile in the United States.
Public records on Paddock point to an itinerant existence across the West and Southeast parts of America, including stints as an apartment manager and aerospace industry worker. He appeared to be settling into a quiet life when he bought a home in a Nevada retirement community a few years ago.
His brother, Eric, described Stephen Paddock as financially well-off and an enthusiast of video poker games and cruises.
“It just makes less sense the more we use any kind of reason to figure it out,” Eric Paddock said in a text message on Tuesday. He added that he had not yet talked to Danley.
“Mary Lou is absolutely the closest person to Steve,” he wrote. “We are going to let her contact us if and when she decides she wants to.”
At his suite at the Mandalay Bay hotel, police found 23 guns.
When they searched his car they found a supply of ammonium nitrate, a fertilizer that can be formed into explosives. Ammonium nitrate was used in the 1995 Oklahoma City bombing of a federal office building that killed 168 people, Lombardo said.
Police found another 19 firearms, explosives and thousands of rounds of ammunition at Paddock’s home in Mesquite, 82 miles northeast of Las Vegas.
Police obtained a warrant to search a second house connected to Paddock in Reno, Nevada.
Chris Sullivan, the owner of Mesquite’s Guns & Guitars shop, issued a statement confirming that Paddock was a customer who cleared background checks and said his business was cooperating with investigators.
Lombardo said investigators knew a gun dealer had come forward to say that he had sold weapons to the suspect, but it was not clear if he was referring to Sullivan. He said police were aware of other people engaged in those transactions, including at least one in Arizona.