Las Vegas shooter Stephen Paddock fitted a dozen of his firearms with a deadly device that allowed a semi-automatic weapon to fire up to 800 rounds per minute and “inflict maximum carnage”, officials have said.
The 64-year-old, who shot and killed at least 58 people and injured more than 500 concertgoers on Sunday night, used the device known as a “bump stock”, which is legal in the US.
The device allows a semi-automatic weapon to perform like an automatic firearm, which are strictly regulated under federal law.
Bump stocks are relatively accessible to civilians, with some advertised online for $100.
California Senator Dianne Feinstein has been working on legislation that would ban bump stock modifications.
She said: “In the wake of the deadliest mass shooting in US history, Congress must examine ways to prevent tragedies like this from happening in the future.
“Automatic weapons are illegal, but individuals are still able to purchase bump stocks to allow semi-automatic weapons to fire up to 800 rounds per minute—the rate of automatic weapons—and inflict maximum carnage.
“I’m looking at ways to proceed with legislation to ban bump fire stocks and close this ridiculous loophole for good. Doing nothing in the wake of this tragedy is not an option.”
Donald Trump is due to visit Las Vegas later today. His trip to the Nevada city will be the first time he has had to deal directly with the aftermath of a mass shooting.
Paddock targeted concertgoers at the Route 91 Harvest country music festival from his window on the 32nd floor room of the Mandalay Bay Resort and Casino at about 10.20pm on Sunday local time (6.20am Monday BST).
The retired multimillionaire real-estate investor owned more than 40 firearms, police said.
Police said Paddock targeted the 22,000-strong crowd with for nine to 11 minutes before taking his own life.
He had set up cameras inside and outside his hotel suite so he could see police as they closed in on his location, authorities have confirmed.
Detectives are investigating whether there is any footage of the shooting.
“I anticipate he was looking for anybody coming to take him into custody,” Clark County Sheriff Joseph Lombardo said of the cameras.
Police are also in the process of reviewing body camera footage from officers who were stationed at the music festival, as well as footage from concertgoers and hotel security cameras.
A total of 47 firearms were recovered from three locations searched by investigators - Paddock’s hotel suite, his home in Mesquite, and another property associated with him in Reno, Nevada, according to Jill Snyder, special agent for the US Bureau of Alcohol Tobacco and Firearms.
“Bump fire stock, while simulating automatic fire, do not actually alter the firearm to fire automatically, making them legal under current federal law,” Snyder said.
A dozen of the guns found in Paddock’s hotel room were fitted with the bump stock device.
Snyder said the rifles, shotguns and pistols were purchased across four states - Nevada, Utah, California and Texas.
Bump stocks remain highly controversial devices. In an interview with The Associated Press, Erich Pratt, executive director of Gun Owners of America, defended the use of bump stock devices, which gun advocates say they use for entertainment.
“Ultimately, when Congress... looks at this, they’ll start asking questions about why anybody needs this, and I think the answer is we have a Bill of Rights and not a Bill of Needs,” Pratt told the AP.
Police had put the death toll at 59, not including the gunman, but the coroner’s office revised the tally to 58 dead, plus the shooter, on Tuesday.
Further details about Paddock’s firearms stockpile emerged as his partner Marilou Danley returned to the US.
Danley was filmed arriving at Los Angeles International Airport in a wheelchair.
It is believed the Australian national was visiting family in the Philippines during the massacre.
Images also surfaced on Tuesday of the high rise suite from which Paddock targeted concertgoers.
He smashed two windows with a hammer to open up his sniper’s nest and fire upon crowds.
High end furnishings in the luxury suite from which Paddock unleashed a barrage of gunfire are visible, as are a series of lamps still burning following the deadliest mass shooting in modern US history.
Paddock had been staying in the suite since Thursday, having arrived with ten suitcases, police said.
A search of the suspect’s car turned up a supply of ammonium nitrate, a fertiliser compound that can be used in explosives.
It was used in the 1995 truck bombing of the Alfred P Murrah Federal Building in Oklahoma City that killed 168 people.