The audio published by CBS News captures the SWAT team’s dialogue with HQ as they prepare to storm the room at the Las Vegas hotel.
Paddock is thought to have unleashed a hail of bullets from the room onto the crowd of thousands below. The death toll currently stands at over 50 with some 400 people hospitalised.
An unidentified officer can be heard saying: “We just hit on the suspect’s door. I need everybody in that hallway to be aware of it and get back.
“We need to pop this and see if we get any type of response from this guy, to see if he’s here or if he’s actually moved somewhere else.”
The response from HQ comes back: “Copy. All units on the 32nd floor SWAT has an explosive breach. Everyone in the hallway needs to move back. All units move back.
The officer can be a heard saying: “Breach, breach, breach.” An explosion is heard
Another officer then confirms: “One suspect down in 135, floor 32. Mandalay Bay. I have the floor.”
Stephen Craig Paddock was a resident of Mesquite, Nevada, with no known terror connections. He was found in the room dead, having spent much of the weekend there, police say.
The Nevada native is believed to be a grandfather who lived with Marilou Danley in Babbling Brook Court.
Records show Paddock lived in a three-year-old, £297,554 ($396,000) two-bedroom home in the tiny desert community of Mesquite.
The incident has been confirmed as the deadliest mass shooting in US history, surpassing the Orlando shooting at the Pulse nightclub in June 2016 when 49 people were killed.
Updating reporters on the incident, Joseph Lombardo, the sheriff of the Las Vegas Metropolitan police department, said: “We are looking at in excess of 50 individuals dead and over 200 individuals injured … Obviously this is a tragic incident and one that we have never experienced in this valley. My condolences go out to the loved ones.
Authorities “located numerous firearms” in Paddock’s hotel room as investigations into the incident continue.
Mr Lombardo continued: “All’s we know is that they were rifles. We are executing a search warrant on the room.
“It is going to be a long and tedious investigation. We are bringing in all the resources of the FBI to assist us in this investigation, in particular to their victim witness advocates and their CSI folks to help us process the scene and ensure that we are getting all the evidence that we can possibly obtain.”
Police have also said that Marilou Danley, a woman who is thought to have been his roommate, is no longer believed to have been involved in the shooting.