Since 2014, the
Route 91 Harvest
country music festival has been held annually at Las Vegas Village, a 15-acre (6.1-hectare)
lot on the
Las Vegas Strip used for outdoor performances. The venue is 450 meters (490 yards)
 from the
Mandalay Bay hotel in
 diagonally across the intersection of
Las Vegas Boulevard and Mandalay Bay Road.
Paddock may have researched the possibility of attacking other outdoor concerts, including the
Lollapalooza festival in Chicago in August 2017.
 The week before the shooting, he booked an apartment at
The Ogden in
Downtown Las Vegas, which overlooked the open-air
Life Is Beautiful festival.
Paddock arrived at the Mandalay Bay hotel on September 25, 2017. He booked a suite on the 32nd floor of the hotel, which was diagonally adjacent to his shooting targets in the festival lot.
[a] He placed a
"Do not disturb" sign on his door, organized the room, and stockpiled an arsenal of weapons.
 Clark County Sheriff
Joe Lombardo said Paddock carried more than ten suitcases into his hotel suite during his preparation for the shooting.
A bump fire stock, showing how the trigger (red) is pulled by the trigger finger when the receiver is moved forward. It is reset when the receiver moves back due to
Twenty-three firearms, a large quantity of ammunition, and numerous
magazines capable of holding up to 100 rounds apiece were found in the suite.
 The firearms included
AR-15 variants manufactured by
FN Herstal, and
Lewis Machine and Tool Company;
AR-10 pattern rifles; and a handgun.
 Two of the rifles were equipped with
telescopic sights and mounted on tripods.
 In the month preceding the shooting, he attempted to purchase a large quantity of
tracer ammunition, but the gun dealer he approached did not have the item in stock.
 Audio recordings of the attack indicated Paddock sustained a high rate of fire, using either a fully automatic weapon, or a semi-automatic weapon utilizing devices to simulate fully automatic fire.
Bump fire stocks were found on twelve of the guns, which allowed for the recoil to actuate the trigger at a rate of 90 bullets in 10 seconds.
Bureau of Alcohol, Tobacco, Firearms and Explosives determined the guns were legal and legally acquired by Paddock.
Investigators found hidden surveillance cameras that were placed inside and outside the hotel room, presumably so Paddock could monitor the arrival of others.
 The cameras were not in record mode.
 Police said a handwritten note found in the room indicated Paddock had been calculating the distance, wind, and trajectory from his 32nd floor hotel suite to the concertgoers he was targeting on the festival lot.
At a press conference on October 4, Sheriff Lombardo stated there was evidence—which he declined to discuss—that Paddock intended to escape the scene, and that Paddock may have had assistance from an accomplice.
 Investigators searched Paddock's room and found a
bulletproof vest and
breathing apparatus, which were survival gear that Paddock never used.