On Sunday night, Rayne Valentine finished his shift at Kings County Hospital in Brooklyn around midnight. A 32-year-old black man, Valentine has worked there transporting patients and medicines and loading bodies of the deceased — many from covid-19 — onto refrigerator trucks since March, when he lost his position as a chef after the restaurant he worked at was forced to close. On his way to the subway, Valentine says he heard a scream and saw several police officers chasing and then piling onto a young man, with one officer smashing the kid with a baton. “Yo,” Valentine called out, then grabbed his phone and began filming. “Back up,” the officers shouted. “I am backing up,” Valentine said, but the police jumped him. “I’m just trying to get home from work.” “Well you picked the wrong time,” one laughed, as they continued to pound him with their batons.

By the time they left him, bleeding and bruised, his skull was cracked. Emergency room doctors at his hospital put seven staples in his head. (Rayne’s story was first reported by the Daily Beast; contacted by The Washington Post for comment, New York Police Department Sgt. Mary Frances O’Donnell said the case is under internal investigation.) Just a week ago, Valentine says, the police were applauding him for his contribution to fighting the pandemic.

“It is wild here,” Gina Arias, of the Justice Committee in New York, told me. “It has become a free-for-all.”

Police swung batons at protesters in the Bronx on Thursday night, enforcing the city’s curfew as soon as 8 p.m. arrived. It’s not just in New York. Los Angeles police beat protesters there Thursday night, too — as did officers in Philadelphia. In Buffalo, officers shoved a 75-year-old man to the ground Thursday while enforcing curfew, causing him to hit his head on the sidewalk. He was taken to a hospital with a serious head injury. In Huntsville, Ala., police fired so many rounds of rubber bullets and tear gas at chanting protesters that one reporter called it a war zone. In Louisville, police shot pepper balls at a journalist on live TV; in Washington, D.C., U.S. Park Police used their shields to beat journalists as officials cleared Lafayette Square before President Trump’s photo op there Monday.

And yet, at the same time police are attacking protesters and journalists, they’re failing to protect large parts of many cities from arson, looting and vandalism. High-end shopping districts in Manhattan suffered widespread damage and theft. In Chicago, marauding gangs terrorize neighborhoods at night, while police pepper-spray peaceful protesters in the face, such as Gianna Wheeler, one of my undergraduate students. In Minneapolis, families peaceably assembled on a closed highway were forced to flee a truck that drove into the area. As police headed to the scene, they pepper-sprayed protesters they passed.

For decades, police have drawn a sharp line between protest and criminal policing. Criminal police work happened largely in vulnerable black and Latino communities, where far more residents have been victims of crime than perpetrators. In these invisible edges of the city, however, police officers operate with impunity — and some, a small minority, are killers. They are protected by a blue wall of silence: district attorneys who rarely and only reluctantly indict officers and police unions that vigorously defend them. Police commanders often punish offenders by transferring them to even poorer, more defenseless communities. When riots happen, it’s usually in these neighborhoods, fueled by police killings of unarmed residents and the inability of families, friends and neighbors to find justice.

Protest policing, in contrast, usually occurs in city centers. Police there tend to be more restrained and professional. Few middle- and upper-class whites ever see the kind of policing poor people of color experience daily. In city centers, carefully choreographed interactions between protesters and police have become so routine that some activists worry that they have lost the capacity to surprise and disrupt.

The kind of policing the United States is seeing this week — riot policing — lies somewhere in the middle. As with protest policing, officers are usually outnumbered. As with criminal policing, engagement with the public happens mostly in disadvantaged neighborhoods among young people of color. The result has been a series of confrontations between police and protesters where the police have often escalated, rather than calmed, conflict — if not expressly started it. Night after night, marches against police impunity are being met by police who act with impunity.

That isn’t a new phenomenon. Pastor Cori Bush told me about a night shortly after Michael Brown was killed in Ferguson, Mo., in 2014, and the city erupted in protest: “What I saw was tanks. My god, I thought, a regular army. It was unbelievable to me that this was not only happening in America to American citizens, but that it was happening to supposedly save other American citizens, in light of a tragedy that should never have happened. The rights that are supposed to protect us were working against us. We said to the police ‘who do you protect, who do you serve?’ ”

The distinction between riot and protest is partly one of race and class. But it is also one of planning, legality and organization. Riots are spontaneous outbursts by young people who have reached their limit. As one organizer in a “hot” Paris suburb put it, it is how the youth “externalize their internal explosions. Some kids in pain cut themselves. These kids, instead of cutting themselves, set things on fire. It is like getting rid of all this pain inside and throwing it outside.” But not all assaults on property, whether arson, vandalism or looting, constitute riots. And there is reason to believe that rather than riots, what we are seeing today is a bifurcated response: nonviolent mass action on the one hand, and some opportunistic but sometimes organized attacks on property on the other.

This combination has made traditional policing strategies counterproductive, unable to preserve protesters’ First Amendment rights or to protect against other crimes.

Large numbers of Americans across the country are marching for civil rights, not rioting. They are calling for the equal administration of justice and the end of impunity for police. These demands have no connection to those engaged in arson, looting and property destruction. And as marches become more organized and disciplined, they are exerting increased control over vandals: Some black protesters have seized and passed white vandals to the police.

No feature of a racially divided society installs the message of subjugation more forcefully than police. Allene Person told me she became so depressed that her legs wouldn’t function after police killed her son in January 2007 in the Bronx. Nicholas Heyward was kept awake by guilt: If only he had taken his son with him, the police officer would not have shot the 13-year old, Nicholas Heyward Jr., while he was playing with his friends on the stairs of their apartment building in Brooklyn. Both parents died prematurely. A Boston University School of Health/University of Pennsylvania study found that in neighborhoods where there were higher rates of unarmed African Americans killed, residents had higher rates of depression and premature deaths.

We may yet see justice in Minnesota. The governor has asked Attorney General Keith Ellison to prosecute Floyd’s death as murder and demanded that the entire police department be investigated. More states should consider such measures, which can help: The relationships between police and the community has improved dramatically since the Camden, N.J., police chief rebuilt the department from the bottom up in 2013. And police killings of unarmed people have stopped almost entirely in New York State since Democratic Gov. Andrew M. Cuomo (at the request of mothers of children killed by police) issued an executive order July 2015 making the state’s attorney general the special prosecutor for all cases where police kill an unarmed person.

When police believe that they will be held accountable for their actions, they hesitate before using lethal violence. Unfortunately, as the protests this week are revealing, they too often know they won’t be.