Since the start of the protests ignited by the police killing of George Floyd in May, cities across the country have seen an alarming spike in violent crime . In New York, 64 people were shot over the Fourth of July weekend. Brooklyns Canarsie neighborhood had three drive-by shootings in a single day. In total, the recent shootings in New York City represent a 210% increase over the same time period in 2019.

Other cities are showing similar trends. In Dallas, violent crime has increased more than 14% since April. Philadelphia has already logged 210 homicides in 2020, the highest death toll since 2007.

Police and politicians have blamed protesters for the rise in violence.

There is a feeling on the street that the police are handcuffed, that they are not out there as aggressively as we were in the past, New York Police Department Chief Terence Monahan said on a local radio show this week. All the rhetoric of Defund the police, get rid of the police, abolish the police, thats got to end. That has to stop

President Donald Trump claimed this week that Chicago, where shootings have also increased, was worse than any war zone and that a vicious assault on police officers was to blame for the rise in crime.

But while the increase in crime is real, there is no evidence to suggest that the protests are to blame.

America is in the midst of three unprecedented events a pandemic, a nationwide uprising over racial injustice and a collapsing economy that affect crime in overlapping ways. Many of the cities with increases in violence in July had seen significant decreases over the previous three months. The current spike may simply mean that whatever grudges Americans held against each other, they managed to wait until now to carry them out.

Nor is the link between police activity and violent crime as straightforward as politicians make it out to be.

People imagine that theres a bunch of criminals out there and that without police, all those criminals would immediately start doing violence, said Monica Bell, a Yale professor who studies segregation and policing . But that doesnt line up with what decades of social science teaches us about why people commit crime.

This Has Happened Before

This is not the first time violent crime has spiked following protests against police brutality. After the police killing of Michael Brown in Ferguson, Missouri, in 2014 and the ensuing unrest, numerous cities recorded an uptick in violence and a decline in arrests.

Police named the phenomenon The Ferguson Effect and argued that protests against police violence had made law enforcement officers afraid to do their jobs. In response to the more cautious police forces, criminals had become more brazen in carrying out assaults and murders.

We have allowed our police department to get fetal and it is having a direct consequence [on crime], then-Chicago Mayor Rahm Emanuel said in 2015 . They dont want to be a news story themselves, they dont want their career ended early, and its having an impact.

The difference now is that researchers know much more about this effect than they did five years ago. Though reports of crimes did indeed spike following the Ferguson protests, arrest rates had been declining for years. There was no evidence that the demonstrations had affected police behavior, nor that the smaller number of arrests had encouraged crime.

Richard Rosenfeld, a criminologist at the University of Missouri-St. Louis who co-wrote the definitive study on the effect, said that what really happened after the 2014 Ferguson protests was the opposite of what law enforcement officials and pundits hypothesized.

Police werent pulling back from communities, communities were pulling back from police, Rosenfeld said. In other words, no one wanted to call the police if they could help it, even if they were having a problem with another person.

Rosenfelds finding aligns with years of research showing that minority communities are becoming less likely to trust police departments. A 2017 study found that 75% of Blacks and Hispanics thought police treated them worse than whites. Another found that just 28% of minorities trusted police to respond to their concerns. Every time police commit a high-profile incident of violence, this distrust spikes even higher.

The rise in crime in 2015 was about the deteriorating relationship between police and communities of color, Rosenfeld said. When trust in police falls, more people decide they dont want to have anything to do with the police. That means that when disputes arise, theyre more likely to take matters into their own hands.