If the Nevada gunman, who killed at least 58 and wounded at least 500 more, was using an automatic weapon, it would be the first time in the history of the American mass shooting epidemic that such a weapon has been used, an expert said.
“I just don’t know of any other case where the perpetrator used an automatic rifle,” said Jack Levin, professor emeritus at Northeastern University, who has co-authored several books on the rise in mass shootings, which he traces to the late 1960s and early 1970s.
Levin said he was almost 100 percent sure that the gunman was using an automatic rifle. “A semiautomatic would not have been capable of firing so rapidly,” he said.
Uniform, rapidfire pops can be heard on video of the incident, suggesting an automatic weapon, which can spray bullets when the trigger is held down, was used — or a weapon modified to act as one.
In mass shootings, usually, “the weapon of choice is a semiautomatic rifle or handgun,” Levin said. “It’s much more difficult to get an automatic rifle. It’s quite easy to get a semiautomatic.”
Adam Winkler, a law professor at the University of California Los Angeles who is an expert on the Second Amendment, agreed. “Automatic weapons are hard to get. They’re very expensive. So, as a result, they’re not often used in gun crime,” he said.
Winkler said they have been used in the past, though, pointing to a Prohibition Era example of a deadly mass shooting using automatic weapons, the St. Valentine’s Day massacre. In that 1929 case, members of Al Capone’s gang murdered seven people in Chicago with machine guns. The incident helped lead to the first federal law restricting access to machine guns, he said.
Owning fully automatic machine guns is legal in Nevada, as long as they are “registered and possessed in compliance with all federal laws and regulations,” the NRA Institute for Legislative Action website said.
Federal law bans the use of newly manufactured machine guns, but allows the transfer of machine guns lawfully owned before May 19, 1986, if the transfer is approved by federal authorities, according to the Law Center to Prevent Gun Violence.
As of November 2006, the national registry of machine guns contained registrations for 391,532 machine guns, the center said on its website.
Winkler said that in order to legally get a machine gun in Nevada, a prospective owner must get a federal license and go through an extensive federal background check that is more intense than the background check for other guns.
The rapid firing in the Las Vegas incident could also be explained by commercially available workarounds that allow semi-automatic rifles — which fire only one shot when the trigger is pulled — to fire a rapid succession of shots.
It’s easier to get other types of guns in Nevada.
Nevada has a gun rights amendment enshrined in its state constitution.
“Every citizen has the right to keep and bear arms for security and defense, for lawful hunting and recreational use and for other lawful purposes,” according to Article 1, Section 11 of the state constitution.
No state permit is required to possess or purchase a rifle, shotgun, or handgun, according to the NRA website.
While a permit is required to carry a concealed firearm, it’s legal to carry one in the open, according to the website.
Nevada does require that people who are subject to a domestic violence protective order give up their guns; and it submits mental health records to the national database for use in background checks, according to the Law Center.
But it does not limit the number of firearms someone can purchase at one time or impose a waiting period, said the center, which gave the state a C- grade for its gun regulations.
“We are saddened & sickened to wake up to news of a horrific mass shooting on the Las Vegas Strip,” the center said in a tweet this morning.
Background checks are required for anyone buying a gun from a federally licensed gun dealer. A law requiring background checks for private-party gun sales in Nevada was passed in a referendum in 2016 but later deemed unenforceable by the state attorney general, the Las Vegas Review-Journal reported.
Jeremiah Manion of the Globe staff contributed to this report.