An audio recording of police at the moment they stormed Stephen Paddock's room at the Mandalay Bay Hotel and Casino has been released.
Police can be heard clearing the hallway of other guests and warning nearby police officers that they would be blasting the door of the Las Vegas hotel open.
Officers at the concert of the Route 91 Havest Festival had seen the hail of gunfire coming from this particular window on the 32nd floor.
"They could see that the rounds were coming from that particular location as heavy fire, automatic fire at times. And so they were corralling all of the people that were actually at the concert into… behind a block wall," Las Vegas Police undersheriff Kevin McHaill told NBC News.
"We need to pop this and see if we get any further response from this guy to see if he's in here or actually moved somewhere else," one officer said
Another special weapons and tactics (SWAT) team officer yelled "breach, breach, breach" as an explosive was used to blow open the door.
Mr Paddock, 64, allegedly shot down from his window onto a crowd of 22,000 people watching country music star Jason Aldean perform at the Route 91 Harvest Festival on the Vegas Strip.
At least 50 people have been killed and over 400 were taken to hospital with injuries after several rounds of bullets were shot.
Mr Paddock had reportedly checked into the room three or four days earlier.
Las Vegas police think he shot himself just ahead of their arrival at his room, where they found more than ten guns as well as other weapons and ammunition.
His residence in Mesquite, Nevada retirement community, approximately 80 miles northeast of Las Vegas, is also being searched by police.
