Before any information had been released about the shooter’s identity, or where and how he acquired the arsenal of 42 guns, 23 of which were eventually discovered in his hotel room, one Connecticut senator was already making headlines by exhorting Congress to “get off its ass” and pass gun-control legislation, officially marking the beginning of another contentious chapter in America's perennial gun-control debate.
“This must stop," Murphy said. "It is positively infuriating that my colleagues in Congress are so afraid of the gun industry that they pretend there aren't public policy responses to this epidemic."
He added: "The thoughts and prayers of politicians are cruelly hollow if they are paired with continued legislative indifference. It's time for Congress to get off its ass and do something."
Shortly afterward, the White House warned lawmakers not to turn the shooting into a “political debate” about gun control before all the facts have been determined. This turned out to be a prescient, because, as the public would later learn, it appears that Steve Paddock, the shooter, purchased his guns legally.
Paddock, who was described by his brother as a millionaire real-estate investor, had no criminal history nor any history of mental illness. Before purchasing guns from two licensed dealers earlier this year, Paddock passed federally mandated background checks. In an interview with NBC, the owner of a gun dealer where Paddock purchased weapons earlier this year said ATF agents had interviewed the employee who made the sale, and confirmed that the dealer had followed all legally necessary procedures before completing the sales.
David Familglietti of New Frontier said that Paddock purchased a rifle and a shotgun in the spring and that agents from the Bureau of Alcohol, Tobacco, Firearms and Explosives interviewed the employee who handled the sale.
"The rifle was not fully automatic, and a shotgun isn't capable of shooting from where he was," Famiglietti told NBC News when asked whether it was possible that the guns were used in the mass shooting.
"He's only shopped there once, so it wasn't someone we knew personally," he said.
"We're very sad about the news of this tragedy. We're in the business of selling firearms legally and took all precautions on this sale, as we do with all sales. My staff takes their job very seriously, and if there were any 'red flags,' the sale would have halted immediately."
In other words, as much as lawmakers would like to feel like they're taken action to prevent more deadly mass shootings, gun control “improvements” like mandating background checks for all gun sales - a proposal that was championed by Murphy and other Dems following last year’s shooting at the Pulse nightclub – wouldn’t have prevented Sunday's night's massacre.
Separately, the purchasing of fully automatic weapons has been significantly restricted in the U.S. since the 1930s, and was effectively outlawed in 1986 when the federal National Firearms Act was amended to further prohibit the transfer or possession of machine guns by civilians – though there’s an exception for weapons manufactured and registered before the law took effect. With a semi-automatic weapon, a shooter must pull the trigger once for each round fired. With a fully automatic firearm, pull the trigger once and the weapon will fire until the magazine is empty.
In Paddock’s case, tighter restrictions on gun sales likely wouldn’t have made a difference: He used a device called a "bump-stock" to convert semi-automatic rifles into automatic weapons, according to Bloomberg. The bump-stock device essentially replaces the gun's shoulder rest, with a "support step" that covers the trigger opening. By holding the pistol grip with one hand and pushing forward on the barrel with the other, the shooter's finger comes in contact with the trigger. The recoil causes the gun to buck back and forth, "bumping" the trigger.
Technically, that means the finger is pulling the trigger for each round fired, keeping the weapon a legal semi-automatic. Bump stocks, gat cranks and other types of weapons-modification tools exist in a legal grey area; they’re widely sold, but not strictly legal. Paddock had two bump stocks, according to investigators who spoke with the AP under the condition of anonymity.
The devices have attracted scrutiny in recent years from authorities.
California Sen. Dianne Feinstein has long railed against them. Several years ago, she told The Associated Press she was concerned about the emergence of new technologies that could retrofit firearms to make them fully automatic.
"This replacement shoulder stock turns a semi-automatic rifle into a weapon that can fire at a rate of 400 to 800 rounds per minute," she said.
Police have yet to determine whether Paddock purchased the bump stocks legally or not.
Meanwhile, as NBC reports, a second firearms dealer - the owner of a shop called Guns & Guitars - confirmed to the ATF that Paddock had passed federally mandated background checks.
Christopher Sullivan, general manager of Guns & Guitars, did not say what weapons Paddock, who lived in Mesquite, had bought.
"All necessary background checks and procedures were followed, as required by local, state, and federal law. He never gave any indication or reason to believe he was unstable or unfit at any time," Sullivan said in a statement.
"We are currently cooperating with the ongoing investigation by local and federal law enforcement in any way we can," he said, adding, "We mourn for this tragedy and our thoughts and prayers are with the families of the lost and injured."
At least three other gun shops and ranges in the Las Vegas area said they had been in contact with law enforcement about Paddock but declined to discuss any purchases or visits he made.
Because the federal gun-sales tracing system is woefully out of date, it could be days before authorities determine the provenance of all 23 weapons in Paddock’s arsenal.
After the Pulse shooting, Democratic lawmakers staged a series of sit-ins and other demonstrations meant to draw attention to their push to pass gun control. However, the gun-control measures they were pushing ultimately failed. Already, some lawmakers are demanding another gun-control bill, before police have even determined how Paddock acquired his arsenal. During the shooting, which occurred late Sunday night, Paddock killed nearly 60 people, and injured more than 500, when he started firing from a window on the 32nd floor of the Mandalay Bay resort and casino, at a distance of more than 1,200 feet from his targets - about the length of the Empire State building.