Stephen Paddock: Police discovered Las Vegas gunman's hotel location from smoke alarm

Rapid gunfire likely to have triggered device, pinpointing 64-year-old's hideout in hotel of 3,309 rooms

Las Vegas police were able to rapidly track down "psychopath" shooter Stephen Paddock as he carried out his deadly assault on concert goers after a smoke alarm was triggered in his room.

Police stormed the 32nd floor of the Mandalay Bay Resort and Casino on Sunday from where the 64-year-old had been raining gunfire onto crowds below, killing 59 and injuring at least 500 more.

The retired accountant killed himself before police arrived, but an arsenal of 23 weapons was found in the room, including two "bump stock" devices — used to let rifles fire continuously.

The attack was meticulously planned but an oversight by Paddock led to police being able to pinpoint his exact location.

Smoke filled the hotel room as he unloaded round after round into crowds, triggering the alarm and leading police to his door, Randy Sutton, a retired lieutenant with the Las Vegas Metropolitan Police Department, told the Washington Post.

“He rained down hell on those people. Hundreds of rounds. The sheriff said that there were several firearms found in the room. He was extremely well armed. He must have brought plenty more ammunition, already loaded into magazines," he added.

The alarm allowed the SWAT team to home in on Paddock's position within 20 minutes of the first 911 call.

A floor-by-floor search of the hotel, which has 3,309 rooms and a 135,000-square-foot casino, would have taken considerably longer.

US President Donald Trump praised the rapid police response to the shooting in the aftermath, calling it a "miracle".

“The police department, they’ve done such an incredible job,” he said. “And we’ll be talking about gun laws as time goes on. But I do have to say, how quickly the police department was able to get in was really very much of a miracle. They’ve done an amazing job.”

It took 72 minutes from the first 911 call being placed to when police eventually stormed Paddock's room.