Was Derrick Chauvin arrested because the investigation into the death of George Floyd has reached a conclusion? Or did Minnesota state police arrest him under the seldom-used “please stop rioting” clause? At the end of today’s press conference, public safety commissioner John Harrington — who had earlier called Floyd’s death a “murder” — announced the arrest of the officer whose knee appeared to choke Floyd to death:

NEW: Minnesota Department of Public Safety Commissioner John Harrington said he just received information that the officer identified as Derrick Chauvin in the death of George Floyd has been taken into custody by the BCA

— Briana Bierschbach (@bbierschbach) May 29, 2020

Minnesota Department of Public Safety Commissioner John Harrington said he just received information that the officer identified as Derrick Chauvin in the death of George Floyd has been taken into custody by the Bureau of Criminal Apprehension.

It’s entirely possible that the investigation has been completed. The videos of Floyd’s last minutes of life are fairly powerful evidence, after all. However, that’s not what officials were saying even just a few minutes before this announcement. Earlier, Attorney General Keith Ellison had spent the morning promising “swift” justice in the case — wisely or not. In that, Ellison had plenty of company, but Ellison kicked it off this morning on CNN. Just have patience, Ellison pleaded, to make sure they have an “air tight” case first:

Minnesota Attorney General Keith Ellison said Friday that he has “every expectation” authorities will press charges against the Minneapolis police officers involved in the death this week of George Floyd.

In a live interview on CNN, Ellison attributed the lack of charges several days since Floyd died to prosecutors with the Hennepin County Attorney’s Office “trying to be careful” to make sure they have a case that is “air tight” and won’t fall apart because of pressure to file more quickly than the evidence allows.

“I have every expectation that they will be [filed]” soon, said Ellison, while pointing out that his office is not the one to make charges happen.

At the same time, he said, patience among the public is needed because, “If it’s not a solid case, we will be sorry later.”

A bit later, Ellison tried to add a bit more nuance, noting the legal issues of an appearance of a directed result in such an investigation. “For me to make a legal comment on what the evidence will show,” Ellison said in a video clip from The Hill, “would not be in the best interest of the prosecution.” Still, Ellison argued that a death in custody from “reckless disregard” has “legal ramifications”:

Minnesota Attorney General Keith Ellison: "We are investigating this case expeditiously. We will charge it appropriately and we will seek the proper consequences." #GeorgeFloyd pic.twitter.com/f5DQ6wabhz

— The Hill (@thehill) May 29, 2020

Well, yes, but usually that argument gets made in an indictment. Does Ellison have one in hand? Actually, Ellison conceded in the press conference this morning, his office won’t necessarily produce one at all. Minnesota law puts Hennepin County as the primary prosecutorial entity, not the state. Despite that, Ellison declared that the case had to proceed “swiftly”:

“The wheels of justice must turn swiftly," Minnesota Attorney General Keith Ellison says about George Floyd's case https://t.co/BXX2uPXfEj pic.twitter.com/QNLYPUUHzD

— CBS News (@CBSNews) May 29, 2020

All of this sounds like official expressions of a directed outcome, or at least very broad hints to Hennepin County’s district attorney’s office. The videos certainly support those arguments, but this creates a problem if the wheels of justice are to roll to a conclusion that Ellison and others will like.

We’ll get to that in a moment, but let’s not leave all of this entirely on Ellison. At the same press conference, commissioner of public safety John Harrington called Floyd’s death a “murder,” repeating it and declaring that the video was enough for him to reach that conclusion. And Minnesota’s top executive, governor Tim Walz, also declared in the same presser that he expected action to be “swift”:

Gov. Tim Walz said he has an expectation that “swift” justice will be carried against the police officers involved in the death of George Floyd.

“It is my expectation that justice for the officers involved in this will be swift, that it will come in a timely manner, that it will be fair. That is what we’ve asked for. I have been in contact with Hennepin County attorney, and I am confident that those very things I just said will happen,” Walz said.

This public pressure to charge the four officers — including Minneapolis mayor Jacob Frey’s demand to arrest them even before the investigation concluded — creates a number of problems in securing a conviction. For one thing, it makes an argument that the charges were politically motivated pretty easy for the defense, once charges do get filed. They will have plenty of video evidence to use in arguing that the city made the officers into scapegoats in an attempt to pander to public outrage. That’s not entirely untrue either, even if the evidence at hand also makes probable cause for arrest and indictment clear too. In fact, it’s fairly obvious that these politicians are talking this way for political purposes.

The next problem will be venue and voir dire. With elected officials airing their conclusions all over local and national media even before charges get filed, the defense will also argue that they cannot get a fair trial in the Twin Cities. That might be a winning argument anyway, under the circumstances, but all of this doesn’t help. A judge might well decide that the venue and jury pool has been tainted and decide to send the trial to another county with some distance from the violence — say, Dakota County, whose seat of Hastings is 30 miles from downtown Minneapolis, and culturally practically another world. Any defense attorney worth his/her salt would fight tooth and nail for that change of venue.

Once the venue’s settled, attorneys can then pick off anyone who heard Harrington, Ellison, and Walz make these promises to prosecute. Or, failing that, use that knowledge to underscore the argument that the only motive for charging the officers was to save the bacon of elected officials under fire in a days-long riot.

Would that work? With the videos in hand, it might not get an acquittal, but it only takes one person to hang a jury. That’s why it’s best to keep one’s mouth shut about ongoing investigations in the first place — and the more high profile the case, the tighter the mouth should get.

Update: It took a while, but the charge has finally been released:

The former police officer who was seen on video using his knee to pin down George Floyd, a black man who later died, has been taken into custody, the authorities announced on Friday, after days of protests escalated overnight with the burning of a Minneapolis police station.

The officer, Derek Chauvin, who is white, was arrested by the Minnesota Bureau of Criminal Apprehension on Friday, John Harrington, the commissioner of the Minnesota Department of Public Safety, said at a brief news conference.

Mike Freeman, the Hennepin County attorney, said that Mr. Chauvin had been arrested on charges of murder and manslaughter. He said the investigation was ongoing regarding the other three officers who were present at the scene.

The inclusion of the lesser charge in the indictment hints that prosecutors might not be fully comfortable with establishing either intent or reckless disregard. That’s an interesting development. That might complicate a federal case for civil-rights violations, as intent would have to be part of that crime.