The fire-scarred entrance to the Minneapolis Police Department’s Third Precinct building on Saturday, in the wake of protests over the death of George Floyd in police custody. (The Minnesota Star Tribune)

We've just had a week like we may never see again. Lord, may we never see a week like that again.

Readers know the context, but we'll recap it briefly for the historical record: A Minneapolis cop kneels on the neck of a prone, handcuffed suspect who complains that he can't breathe. The suspect dies. The event is captured on video and the city erupts in protest, because this is only the most recent loss of a black citizen's life during an encounter with the law and the police culpability strikes most people as hardly debatable.

But the earnest protests are overwhelmed by rioters who spend the next several days and nights smashing windows, looting stores and torching buildings, including a police precinct. The Twin Cities and Minnesota, heretofore known if not exactly famed, earn notoriety by self-destructing as the world watches.

By the fourth day the officer has been arrested and charged, and by the sixth day authorities backed by the National Guard have tentatively reasserted control. It is both that simple and much more complicated, of course. Here are some further questions and observations.

The Saturday-night show of force was necessary after a bungled early response.

The images of National Guard vehicles streaming into the Twin Cities Saturday were both troubling and reassuring. Gov. Tim Walz said repeatedly during the day that curfews would be enforced and that law enforcement intended to restore control. Minnesotans will long debate whether the full-force response would have been needed if officials had moved more decisively earlier in the week, but the widespread chaos had to be stopped.

A coordinated state, local response is critical.

After the worst of the rioting Thursday night and early Friday, Walz called the city's response an "abject failure" during a news conference in which he appeared without Minneapolis Mayor Jacob Frey or St. Paul Mayor Melvin Carter. Walz failed to note that Frey called for the Guard as early as Wednesday. On Saturday and Sunday, the three leaders addressed the news media together and, more important, appeared to be back on the same page.

Officials promised to protect news media but have failed to do so.

Walz and law enforcement officials repeatedly promised that journalists covering the disturbances would be allowed to do their work, but by Sunday a long list of incidents showed that law enforcement had failed that test, either because of confusion, ineptitude or disdain for journalists.

There were extremists, some from outside Minnesota, who exploited George Floyd's death, but we still have much to learn about them.

Public officials gave conflicting accounts when asked about the extent to which outsiders were involved in the rioting, but Walz said it was clear there was "an organized attempt to destabilize civil society." White supremacists? Anarchists? Members of the antigovernment "Boogaloo Bois"? Star Tribune reporter Stephen Montemayor explored the issue in a disturbing Sunday story, and social-media channels were filled with posts on cars with out-of-state plates or no plates at all on the streets of Minneapolis and St. Paul.

Was the fast, unusual decision to charge Derek Chauvin with murder rushed?

It's a natural question, given that Hennepin County Attorney Mike Freeman himself declared that his office has never charged a police officer so quickly before. Most such charging decisions have come only after months of investigation. There is a reason for usually avoiding haste. Assembling the evidence needed to convict an officer takes time because law enforcement personnel are in a different position from ordinary citizens. Officers have authority and duty to arrest lawbreakers, and they are authorized to use reasonable force when necessary.

So to prove an officer has crossed the line into criminality, a prosecutor must be able to prove, beyond reasonable doubt, that the force used was unreasonable in light of all the circumstances of which the officer was aware. And in homicide cases it must also be proven that the officer intended to cause grave injury or showed a depraved indifference to doing so. It is a heavy burden, and no one should suppose the outcome is certain.

As always, the story becomes more complex as information is revealed.

We started only with the video of Chauvin kneeling on Floyd's neck. In the days following we saw security footage showing his initial interactions with officers, the transcript of the 911 call that brought them to the scene, and the criminal complaint describing how he came to be on the ground. It becomes tragically clear in these details that at several steps the outcome might have been averted.

In those we learn — prospectively — that Floyd acted as if under the influence. That he declined an opportunity to make good on the counterfeit money he allegedly passed. That he was nervous and uncooperative about being put in a squad car. That one of Chauvin's colleagues expressed concern that Floyd might be experiencing "excited delirium," a medical condition that can cause agitation, aggression, acute distress and sudden death.

All this is going to weighed at trial against the nearly nine minutes Chauvin kept Floyd pinned to the ground.

The "blue wall of silence" is disintegrating, slightly.

Janeé Harteau, the former Minneapolis police chief who left her job under pressure in 2017 after the police shooting of Justine Ruszczyk Damond, has said that the police union fought her reform efforts at every turn. Marilyn Mosby, the Baltimore prosecutor who unsuccessfully charged officers in the death of Freddie Gray, described in a recent Washington Post commentary the intimidation she received from both inside and outside the system.

Fortunately, there appears to be a shift in "blue wall" sentiments in response to Floyd's death. A telling comment came from David Roddy, the police chief in Chattanooga, Tenn.: "If you wear a badge and you don't have an issue with this … turn it in."