Gun-violence rates in Philadelphia spiked after coronavirus lockdown measures were put into place in March — and remained at unprecedented levels for the rest of the year, a new study led by a Temple University Hospital trauma surgeon found.

The findings, published this week in JAMA, serve as grim confirmation of what many Philadelphians saw in 2020 firsthand: While much of the country ground to a halt, the city’s gun-violence epidemic raged on.

The research came about as trauma surgeons at Temple and around Philadelphia sought to find an explanation for a sharp increase in gun-violence patients, said the study’s lead author, Jessica H. Beard, assistant professor of surgery and director of trauma research at Temple’s school of medicine.

“This level of increase is kind of unprecedented in our kind of modern era, and those effects can definitely be felt on the day-to-day practice of trauma surgery in the city,” Beard said. The study’s findings, she said, led to a connection between gun violence and COVID-19 as public health crises in Philadelphia.

The study tracked 256 weeks of shooting data in Philadelphia, from January 2016 through the end of November 2020, noting a marked spike in gun violence after March 16, 2020, when nonessential businesses were first closed in the city.

Prior to business restrictions and stay-at-home measures meant to mitigate the virus’ spread, researchers found that an average of 25 people were shot each week in the city. After the pandemic lockdown measures were implemented, that average increased to 46 people shot each week in Philadelphia.

“I think maybe we think of violence a little less than COVID as a public health problem,” she said. “But I think what this highlights is that both are linked, and that there are social and structural factors that drive the incidents of gun violence that we need to be mindful of as we deal with COVID as a major public health problem.”

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However, Beard said, when some lockdown measures were relaxed over the summer, or reinstated in the fall, researchers found gun-violence rates remained largely unmoved. The Temple study also concluded that the Minneapolis police killing of George Floyd in May and the ensuing unrest in Philadelphia were not associated with any significant change in shootings in the city.

In 2020, more than 2,240 people were shot in Philadelphia, a total 40% higher than ever recorded since police began separately tracking data on shooting victims in 2007.

The year was also one of the deadliest in Philadelphia’s history, as nearly 500 people were killed — more than all of 2013 and 2014 combined.

» READ MORE: Only 9% of shootings in Philly have reached a conviction in the last five years

Many societal factors may have played a part in the increase in shootings in a year marked by the pandemic, economic strain, and unrest over racial inequity, researchers noted.

Geographically, much of the city’s gun violence today correlates with the racist practice of redlining, Beard noted, adding that historic disinvestment in some neighborhoods is a “potential explanation” for findings connecting the lockdown measures with more shootings.

“You can imagine that if you take folks who are already stressed and live in places of high levels of disadvantage, and then you enact something like a containment policy without or without enough mitigating factors, then something like violence that we know is so linked with that history of structural violence increases,” she said.

In interviews with The Inquirer last year, city officials, including Mayor Jim Kenney, Police Commissioner Danielle Outlaw, and District Attorney Larry Krasner, said myriad factors contributed to the 2020 spike in gun violence: an increase in financial stress; the pandemic’s effect on policing; trust-shattering behaviors by police; the closure of courts, schools, jobs; and disruption to probation and parole systems.

The findings in Philadelphia echo a deadly nationwide trend. A sample of major U.S. cities found that homicide rates climbed 30% higher in 2020 than in 2019, according to a study by Arnold Ventures and the National Commission on COVID-19.

Nearly six weeks into 2021, Philadelphia’s gun-violence numbers continue to surge.

On Monday, seven people were killed in Philadelphia within 24 hours. As of Tuesday, 62 people had been killed in 2021, up 55% over last year for the same time period, and double the average of the last 14 years, according to police data.

Charting a path for ending a gun-violence epidemic doesn’t have a solution like an infectious disease, “where you give a vaccine and the spike comes down,” Beard said.

”Violence actually kind of begets more violence and increases itself through personal and individual and community-level trauma,” she said. “Only time will tell.”

Staff writer Chris Palmer contributed to this article.

Correction: An earlier version of this article incorrectly identified the name of the journal.