Las Vegas Sherriff Joseph Lombardo released a timeline of the deadly shooting carried out by Stephen Paddock who opened fire on unsuspecting concertgoers and said he found it hard to believe the gunman planned the massacre alone.
Las Vegas Sherriff Joseph Lombardo detailed the carnage carried out by Stephen Paddock, 64, from the 32nd-floor hotel room at the Mandalay Bay Resort and Casino.
The mass shooting killed 58 people and wounded nearly 500 others in a 10-minute barrage of gunfire.
At 10.05pm local time on Sunday, Paddock opened fire on the crowd at the nearby Route 91 Harvest Festival.
Just seven minutes later at 10.12pm, two officers arrived on the 31st floor of the Mandalay Bay hotel and said the gunfire was coming from above them.
Paddock then fired his last shots at 10.15pm as officers got onto the 32nd floor.
A security guard told officers he was shot and gave the location of the shooter's hotel room at 10.18pm.
More than 200 rounds were fired from the room into the hallway.
Between 10.26pm and 10.30pm, eight more police officers reached the 32nd floor of the hotel, and started clearing each room and searching for wounded.
Almost an hour later at 11.20 pm, officers used explosives to breach the door of Paddock's room, which was a suite.
They found him on the ground and discovered a locked bedroom door.
Officers breached the second door at 11.27pm and determined no one else was present in the suite.