Citing an outbreak of three California mass shootings that killed 19 people in a span of 44 hours, President Joe Biden on Tuesday renewed his call for a national ban on assault weapons.

His response follows an extraordinarily high rate of mass killings in the U.S. over three of the past four months.

“Even as we await further details on these shootings, we know the scourge of gun violence across America requires stronger action,” Biden said in a statement. “I once again urge both chambers of Congress to act quickly and deliver this Assault Weapons Ban to my desk, and take action to keep American communities, schools, workplaces, and homes safe.”

James Alan Fox, a Northeastern criminology professor who has been studying mass killings for more than 40 years, says the president should be focused instead on a national ban on large capacity magazines—thereby limiting the number of bullets that can be fired without pausing to reload.

“The issue of an assault weapons ban is a nebulous thing,” says Fox, the Lipman Family Professor of Criminology, Law and Public Policy at Northeastern. “With the assault weapons ban we had in the 1990s, they listed certain weapons as assault weapons—and then the gun manufacturers simply modified them and gave them new model numbers.

“It’s the ability to continue to pull the trigger and refire without reloading that is the issue.”

A 2020 study by Fox showed that states with bans on large-capacity ammunition magazines experienced fewer fatalities and injuries during mass shootings than states that had no limitations on the number of bullets that could be loaded.

Thirty-eight states do not have restrictions on gun magazine capacities.

There have been six mass killings accounting for 39 deaths in the U.S. already this year, according to the Associated Press/USA TODAY/Northeastern University Mass Killing Database, which Fox manages. 

Though there were no mass killings in December, other recent months have been extraordinarily tragic, Fox says.

“Six mass killings in January, 10 in October and nine in November—those numbers are way over the usual rate,” Fox says.

The spree of mass shootings began Saturday near Los Angeles:

• Eleven people were killed Saturday and nine others were wounded at a Monterey Park dance hall as the Asian American community was celebrating Lunar New Year. The 72-year-old suspect, Huu Can Tran, died of a self-inflicted gunshot wound. Minutes after that attack, he had attempted to enter another dance hall in a nearby community, where people disarmed him of a semiautomatic handgun.
• Seven people were killed and one was injured in two shootings—at a mushroom farm and near a trucking facility—on Monday in Half Moon Bay, a small community in the Bay Area. The suspect, Chunli Zhao, 67, was arrested in a sheriff’s parking lot after the shootings. “We do know that some of the victims were Chinese, that the perpetrator was Chinese and that this was an agricultural community—they were agricultural workers,” Half Moon Bay Mayor Deborah Penrose told CNN on Tuesday.
• One person was killed and seven people were injured on Monday night in Oakland. Police said there had been a shooting among several people.

Ian Thomsen is a Northeastern Global News reporter. Email him at i.thomsen@northeastern.edu. Follow him on Twitter @IanatNU.