The US gun lobby, which has seldom embraced new firearms-control measures, voiced a readiness on Thursday to restrict a rifle accessory that enabled a Las Vegas gunman to strafe a crowd with bursts of sustained fire as if from an automatic weapon.
Police have said the gunman, Stephen Paddock, equipped 12 of his weapons with so-called bump-stock devices that allow semi-automatic rifles to operate as if they were fully automatic machine guns, which are otherwise outlawed in the United States.
Authorities said his ability to fire hundreds of rounds per minute over the course of 10 minutes from his perch in a 32nd-floor hotel suite was a major factor in the high casualty count of 58 people killed and hundreds wounded. Paddock, 64, killed himself before police stormed his suite.
The carnage on Sunday night across the street from the Mandalay Bay hotel ranked as the bloodiest mass shooting in modern US history, surpassing the 49 people shot to death last year at a gay nightclub in Orlando, Florida.
The influential National Rifle Association (NRA), which staunchly opposed moves to tighten gun control laws following the Orlando massacre and others, said on Thursday that bump stocks, which remain legal, should be subject to additional regulations.
Senior Republicans also signaled they were ready to deal with the sale of bump stocks - an accessory gun control advocates regard as work-arounds to bans on machine-guns.
Clearly that's something we need to look into, House Speaker Paul Ryan told radio talk show host Hugh Hewitt. I didn't even know what they were until this week ... I think we're quickly coming up to speed with what this is, Ryan said.
The No. 2 Republican senator had called for a review of bump stocks a day earlier. Democrats were already urging new legislation, as the shooting reignited the long-standing US debate over regulation of gun ownership, protected under the Second Amendment of the US Constitution.
US Representative Steve Scalise, a member of the Republican House leadership who is himself a victim of gun violence, voiced concern that hasty congressional action to restrict bump stocks could lead to wider limits on the rights of gun owners.
The NRA called for the US Bureau of Alcohol, Tobacco, Firearms and Explosives to address bump stocks by regulation, rather than opening up the issue to the legislative process.
US President Donald Trump, an outspoken proponent of gun rights during his campaign for the White House, suggested he was open to curbs on bump stocks. Asked by reporters if they should be banned, he replied: We'll be looking into that over the next short period of time.
Investigators remained puzzled at what drove Paddock, a well-off retiree and avid gambler, to assemble an arsenal of nearly 50 firearms, thousands of rounds of ammunition and a supply of explosives before opening fire on a country music festival attended by 20,000 people.
Paddock's girlfriend, Marilou Danley, 62, was questioned by the FBI on Wednesday and said in a statement she never had any inkling of Paddock's plans.
Danley, who returned late on Tuesday from a family visit to the Philippines, is regarded by investigators as a person of interest.” The Australian citizen of Filipino heritage is cooperating fully with authorities, her lawyer said.
She shared Paddock's home at a retirement community in Mesquite, Nevada, northeast of Las Vegas, before traveling to the Philippines in mid-September.