Gun violence is up. It's been up for more than a year.

America is in the midst of a spike in gun violence without recent precedent.

A body is transported from a FedEx facility in Indianapolis on April 16, the day after a gunman killed eight workers there.A J Mast / NYT via Redux file
SHARE THIS —

It may feel like America entered a new wave of gun violence in 2021, but a review of shootings with multiple victims shows that their frequency has been unusually high for more than a year.

Data from the Gun Violence Archive shows that the number of multiple-victim shootings first spiked in April 2020 and has stayed high since. The most recent wave of shootings around the country, including the April 15 attack in Indianapolis where eight people were killed at a FedEx facility, is just the latest symptom of that trend.

View this graphic on nbcnews.com

The deadly pattern has continued this year. There have been 160 shootings from Jan. 1 to April 26 in which four or more people were injured or killed, compared to just over 90 during the same period in 2020. And this year’s total is nearly double the average for the same time period for every year since 2014.

View this graphic on nbcnews.com

There is no federal definition of a mass shooting. The Gun Violence Archive, a nonprofit, nonpartisan research group based in Washington, defines it as a shooting incident in which four or more people are injured or killed, excluding the shooter.

But experts say the focus on high-profile mass shootings, in which a shooter opens fire in a crowded public space, has obscured the rise in lower-profile incidents of gun violence, such as interpersonal disputes or domestic violence incidents.

“If we're talking about mass shootings, those tend to be left out because they're seen as private events,” said Lisa Geller, state affairs manager at the nonprofit Coalition to Stop Gun Violence in Washington. “Some of these high-lethality events are inherently random, but if you include some of the events in private spaces, the role of domestic violence in mass shootings is large.”

The rise in shootings corresponds with an increase in gun sales, which jumped at the outset of the pandemic as stay-at-home orders unleashed a wave of unemployment across the country. FBI background checks, which are conducted when a person attempts to buy a firearm from most dealers, can serve as a proxy for gun sales. In the 13 months since March 2020, the agency has seen 3 million background checks in a month 11 times, after having just one such month between 1998 and February 2020.

View this graphic on nbcnews.com

Lacey Wallace, associate professor of criminal justice at Penn State University Altoona, said that while gun sale increases in previous years were related to personal safety fears or tighter gun laws, the current spike is related to worries unique to the pandemic.

“The gun-purchasing spikes we've seen in the past year are different,” Wallace said. “This time instead of it being driven by more restrictive policies, it’s more Covid-specific things: uncertainty about the future, fear of people from foreign countries, fear of the economy tanking.”

The jump in gun sales alarms gun safety advocates. The Coalition to Stop Gun Violence warned in April 2020 that guns in the home posed a risk of rises in domestic violence and gun suicides.

“2020 saw record gun sales,” Geller said. “We know that when there are more guns, there is more gun violence.”

There are many possible reasons for the rise in shootings over the last year, experts say, from the stress of the physical health and financial challenges of the pandemic to harder-to-access mental health services.

“I think we are very aware that food insecurity, isolation and lack of social services are risk factors for many forms of gun violence,” Geller said.

"It really underscores the need for social services, for grassroots violence prevention and intervention," said Ari Davis, the coalition's senior policy analyst. "Some of that was not possible during the pandemic."

Despite the overall increase in gun violence, experts agree there was a slight pause last year in high-profile, public-place mass shootings. Such pauses wouldn't be reflected in the Gun Violence Archive data, which doesn't distinguish domestic and gang shootings from more public incidents.

Geller attributed the pause to stay-at-home orders, which kept people out of public places: “You couldn't have a school shooting if a school was closed.”

But that pause could be over as the pandemic begins to recede, said Jeffrey Simon, a visiting political science lecturer at the University of California, Los Angeles. He said the return of crowds are creating so-called soft-targets: low-security public gatherings that are susceptible to mass shootings.

“Last year there were fewer opportunities for people to target places,” Simon said. “Now with things opening up, there are more targets.”

CORRECTION (April 26, 2021, 3:00 p.m.): A previous version of this article misattributed a quote about domestic violence shootings being seen as private events. It was said by Lisa Geller, the state affairs manager of the Coalition to Stop Gun Violence, not Ari Davis, a senior policy analyst at the coalition.

CORRECTION (May 5, 2021: 9:30 a.m. ET): A previous version of this article misspelled the name of the state affairs manager at the Coalition to Stop Gun Violence. She is Lisa Geller, not Lisa Gellar.