The dangerous pace of mass shootings escalated in 2020 during the Covid-19 pandemic and has persisted since then. Between 2019 and 2020, the total number of mass shootings each year jumped from 414 to 610. Then, 2021 became the worst year for mass shootings since GVA began tracking them in 2013, with 690 across 44 states and Washington, DC. There were 656 mass shootings in 2023.

GVA data show mass shootings increased after May 2020, compared with trends in previous years. Shootings doubled in July 2020 compared with the year before, as researchers noted in the journal JAMA Open Network in analyzing GVA data between April 2020 and July 2021.

The increase in mass shootings coincided with an overall rise in gun violence during the pandemic. The US firearm homicide rate in 2020 was the highest recorded since 1994, according to data from the US Centers for Disease Control and Prevention. Between 2019 and 2020, the overall firearm homicide rate increased about 35%, according to the CDC’s Morbidity and Mortality Weekly Report.

CNN reports mass shootings based on data from the Gun Violence Archive, a nonprofit organization that tracks gun violence in the United States. CNN and the GVA define a mass shooting as a shooting that injured or killed four or more people, not including the shooter. The number of mass shootings and casualties is not exact and subject to change as reports from law enforcement, media and other sources GVA relies upon are updated and verified.

These charts include US mass shootings to date that fall under this definition and are updated as soon as new data is available from GVA. Data may lag behind breaking news reporting.

—CNN’s Jacqueline Howard and Lauren Mascarenhas contributed to this report