Murders and manslaughters in the United States rose by 29.4% last year, according to FBI data released Monday, the biggest one-year increase since record keeping began nearly sixty years ago.

Approximately 21,500 killings took place across the country in 2020 – 4,900 more than in 2019.

While overall killings are still well short of highs established in the 1980s and earlier 1990s, several cities including Albuquerque, Memphis, Milwaukee and Des Moines saw more murders than ever before.

A majority of the killings, 77%, involved firearms. That’s up from 67% a decade ago.

Justin Nix, an associate professor of criminology and criminal justice at the university of Nebraska in Omaha, explained the reason behind the horrifying rise in violence to The Washington Post:

Nix said the most likely culprits for the sharp spike in killings is twofold: the pandemic, and what he called a “police legitimacy crisis” brought on by the videotaped killing last year of George Floyd by a police officer in Minneapolis.

That incident and others have caused many people to trust police less, making them less willing to call for help, or provide information to investigators about killings, Nix said. He added that the effect is magnified when officers “de-police” by pulling back from patrol and other duties in the fact of public criticism.

On top of that, Nix said, the data suggests there may be more people carrying and using guns in public spaces, leading to more killings.

The rise in killings corresponds with the economic fallout caused by the pandemic. Millions of Americans lost their jobs and businesses over the past 18 months, causing vast desperation and anxiety. Millions more experienced the trauma of losing a loved one to COVID-19, an event that could lead to anti-social behavior.

The New York Times expands on the role the pandemic played:

The pandemic also meant that police departments sometimes struggled with the number of officers under quarantine, while the pandemic curbed public services like mental health counseling and simultaneously aggravated related problems like homelessness.

“This is a country where everybody is suffering a little post-Covid traumatic syndrome, and not knowing what is going to happen,” said Peter N. Winograd, a professor at the University of New Mexico who works as a consultant for the Albuquerque Police Department. “That is huge.”

In July, Sen. Lindsey Graham, Republican from South Carolina, asked FBI Director Christopher Wray during Congressional testimony if bail reform was partly responsible for the rise in murders. Wray was elusive, saying “one of the causes of the violent crime spike are certain kinds of prosecution practices,” adding that “there’s nothing more disheartening to a law enforcement officer to see somebody that you worked hard to arrest promptly back out committing a crime again.”

In a factcheck, CNN notes that “the majority of cities that have seen increases in crime have not eliminated cash bail.”

Killings have continued to rise in the first half of 2021, but the increase isn’t as stark.