Mass shootings have become increasingly more common, with incidents escalating nationally during the pandemic. While mass shootings in California decreased early in the pandemic, these attacks that injure or kill at least four people have begun to inch up: in 2023, Californians have experienced a mass shooting every six days. The state will need an integrated policy framework to address mass shootings—and gun violence more generally—in order to minimize the prevalence of incidents, reduce their severity, and mitigate the harm that follows.

Early in the pandemic, the number of mass shootings skyrocketed in other states, while easing in California. Before 2020, incidents of mass shootings fluctuated in similar ways for California and the rest of the country—albeit with degrees of difference. That changed in 2020. Mass shootings fell in California, dropping 24% from 51 attacks in 2019 to 39 the next year. By contrast, incidents rose 61% across the United States from 379 to 611 attacks.

Overall, the pandemic rise in mass shootings nationally outpaced California thirteenfold—incidents in other states peaked at 676 shootings in 2021, a 78% jump relative to 379 incidents in 2019. Over the three pandemic years, California incidents rose only 6%, from 51 attacks in 2019 to 54 in 2022.

The recent uptick in California shootings, however, means that they are now occurring more often than in the past. In 2015, a mass shooting happened somewhere in the state every thirteen days. In 2022, a mass shooting occurred every week.

The number of people injured and killed in mass shootings tends to fluctuate because mass shootings are a small component of the larger problem of gun violence, and many factors determine how they unfold. Between 2015 and 2022, an annual average of 7.3 people per one million—or about 2,400 people—were victims of mass shootings around the country, although the national rate each year ranged between 4.8 and 11.2 victims per one million people.

California had the lowest average rate among the most populous US states—at 5.5 victims per one million people, or 24% below the national average. Furthermore, only New York had a lower average rate of mass shooting homicides, at 0.6 per one million people who died as a result of a mass shooting compared to California’s rate of 1.2 people per million.

The recent uptick in mass shootings in California has continued into 2023. In the seven years between 2015 and 2022, the state saw an average of 15 mass shootings between January and May. By 2022, this number had risen to 24 mass shootings statewide within that timeframe. In 2023, the state saw 25 mass shootings during the same period. A mass shooting has occurred every six days in California so far in 2023.

Effective policies to address mass shootings would support a three-pillared strategy that prevents attacks before they occur, reduces injuries and deaths as they happen, and mitigates harm in their aftermath. Studying the effects of such policies will require a data infrastructure that can help the state identify interventions that can be implemented widely and easily maintained.