The household device that led police to killer gunman

A simple smoke alarm installed in a hotel room tipped police off to Stephen Paddock’s location amid the deadliest shooting in US history which saw 59 people die and more than 500 injured.

Las Vegas police lieutenant Randy Sutton said the killer’s room in the Mandalay Bay hotel quickly filled with smoke after he started unloading rounds of ammunition, The Washington Post reports.

It’s believed this helped the SWAT team find Paddock who shot a security guard in the hallway before killing himself.

It saved police checking more than 3,300 hotel rooms.

A second high-powered weapon found inside the 32nd floor hotel room. Source: Boston 25 Twitter
Stephen Paddock gunned down 59 people from inside a Vegas hotel room. Source: Supplied

Lt Sutton said Paddock fired “hundreds of rounds”.

“The sheriff said that there were several firearms found in the room,” he said.

“He was extremely well armed. He must have brought plenty more ammunition, already loaded into magazines.”

The hotel window where Paddock perched himself. Source: AAP
Police say a smoke alarm helped them determine Paddock's location in the Mandalay Bay hotel. Source: AAP

According to the US’s National Air Filtration Association each shot fired “releases a small quantity of harmful dust and gases”.

Gases and particles can build up in firing ranges even where there is appropriate ventilation.

An officer near the scene on October 1. Source: AAP