CNN  — 

As the body counts rise, American cities remain ground zero for a deadly new reality.

And those charged with keeping communities safe and helping flatten the curve of death are under fire and losing confidence from those they are sworn to protect.

This isn’t coronavirus but a plague of violence in many American cities as murders and assaults spike during the global pandemic.

From May to June 2020, homicides in 20 major US cities increased by 37%, led by Chicago, Philadelphia and Milwaukee, according to new data from the nonpartisan Council on Criminal Justice (CCJ) think tank. Aggravated assaults jumped by 35% over the same period of time, while other types of crime were down.

In Chicago, nearly 30 people were shot and three people killed this weekend alone, Chicago Police said Sunday morning. Among those injured are a 12-year-old boy, a 14-year-old boy and two 16-year-old boys in separate shooting incidents.

In New York City, over 40 people were shot in a 48-hour period as of Sunday morning, the New York Police Department said. There were 20 victims as a result of 12 shooting incidents Friday, and 23 victims as a result of 20 shooting incidents Saturday, according to data released by the NYPD.

The CCJ’s data comes as Gallup released new public opinion polling data indicating confidence in law enforcement has fallen to the lowest level in 27 years, with just 48% of respondents indicating a positive view of those who wear the badge.

Both academic researchers and policing experts say identifying a specific reason for the sudden spike in violent crime remains elusive. It could be the result of multiple factors converging as the nation simultaneously grapples with several public safety crises.

“Crime is complicated,” said Chuck Wexler, executive director of the Police Executive Research Forum, a non-profit police research and policy organization. “Murder is complicated. You have to ask yourself what has been going on in these four or five months that would indicate some theory for why this is happening.”

The plague of violence

This year has been one marked by unprecedented tragedy as the nation reels from a public health crisis that has claimed more than 160,000 lives, as well as the questionable deaths of several Black Americans – including George Floyd, Breonna Taylor and Rayshard Brooks – at the hands of police officers.

After Floyd’s death, hundreds of thousands of protesters took to the streets around the country demanding racial justice and an end to excessive use of force by police. While the overwhelming majority of demonstrations were peaceful, some incidents of rioting and looting occurred in places like Minneapolis, Chicago, New York City and Atlanta.

Police officers inspect a damaged Best Buy store on August 10, 2020, after parts of Chicago had widespread looting and vandalism.

While CCJ researchers who examined the recent spikes in homicides and aggravated assaults say it is too soon to draw conclusions on any one contributing factor, they note that the social stress caused by the Covid-19 pandemic and recent national unrest cannot be overlooked.

Policing experts tend to agree.

“It’s a time unlike any other American history,” said Wexler, who noted both the coronavirus pandemic and recent calls for police reform have had an impact on law enforcement.

Wexler said the spread of the coronavirus has likely had a negative impact on both witnesses to crime coming forward, as well as law enforcement agencies themselves hampered as infections spread throughout their ranks.

“Investigations have been impacted,” said Wexler, citing the New York Police Department as one organization that had dozens of officers sidelined due to illness. “If someone has shot someone else, the chances are they’re probably shooting other people. So, if you can’t follow up on those shootings, they’ll likely continue.”

As another possible contributing factor, Wexler said various incidents of social unrest have required law enforcement agencies to pull resources away from patrolling the streets to deal with looting and unrest.

“When you’re spread thin like that, it has an impact on your operations,” he said.

Wexler said he questioned whether the early release of some inmates over fears of Covid-19 spreading in correctional institutions could affect crime on the streets.

Still, he says, there are no easy answers to the surge in homicides and assaults noted by CCJ researchers but believes public officials must study the issue.

Distrust of the police

The global pandemic and increased murder rates are not the only issues plaguing American policing.

In a profession that succeeds or fails largely based on community support, new Gallup polling data shows public confidence in police has hit its lowest level in nearly three decades.

Around 48% of Americans said they have a “great deal” or “quite a lot” of confidence in police, down from 53% the previous year, according to the new poll.