Two more African-American men are dead, in Tulsa, Oklahoma, and Charlotte, North Carolina, shot to death by police officers in a blood-spattered coda to this terrible summer of carnage. With overnight rioting in Charlotte triggered by the shooting there, a U.S. city is again racked by violence and fury amid the spectacle of a community’s open contempt for the police.

The dead man in Tulsa, Terence Crutcher, was unarmed and, judging by the video footage, posed no apparent threat to the officers who accosted him on the road — the most recent in a string of seemingly unwarranted police shootings now so long that disentangling one episode from another requires a feat of memory. The officer who shot Crutcher was white. Whether Crutcher had or had used PCP, as the police suggested, is scant justification for a shooting by an officer who was in no apparent danger when she pulled the trigger.

In Charlotte, the police say an African-American officer opened fire on Keith Lamont Scott only after he brandished a weapon; some relatives say he was carrying a book, and that if a gun was recovered, it was planted by the police. It would be helpful if the police would release whatever video footage they have. Nonetheless, officers were in the neighborhood to serve a warrant on a different person, so it seemed bizarre that Scott, sitting in his car, would threaten them. The circumstances of the incident, coupled with the recent history of police accounts of shootings elsewhere that have been contradicted by the disclosure of video evidence, fed a sense of disbelief in the official narrative in Charlotte.

The year is not yet three-quarters gone, but Scott is one of more than 700 people shot to death by officers in 2016, of whom 164 have been black men.

The rioting in Charlotte, which has left at least 16 police officers injured, is an unacceptable, unjustified act of violence, and rioters should be prosecuted to the full extent of the law. It’s also unsurprising. When blacks represent a quarter of the victims of lethal police-involved shootings nationally — twice their portion of the overall population — and when many of those who die are unarmed, can anyone be amazed that the anger, impotence and sense of injustice pervasive in many African American communities may, in conjunction with another senseless shooting, provide a spark for violence?

In addition, Charlotte may have been especially combustible. In 2013, a police officer there fired a dozen shots at Jonathan Ferrell, a widely admired former college football star, killing him as he sought help after being involved in a single-car accident. The trial of the white officer who shot him, who was charged with voluntary manslaughter, ended with a hung jury, and prosecutors did not seek to retry him.

The violence this time fits a pattern whose complex causes will not fade with the headlines about the most recent shootings. It bespeaks a chronic, deep-seated illness in American society whose pathology is mainly ignored in this electoral season.

Editorial by The Washington Post