Let’s talk about Kimberly Potter, the Minnesota police officer who was recently convicted of manslaughter. This case has been badly reported in the news media; it’s both more simple and more complex than the news reports.

Potter, who’d been a police officer for 26 years, was acting as a Field Training Officer at the time. Here’s a true thing about training: the stuff you learn in a classroom doesn’t always translate well in real life. I’ve done OJT (on the job training) as a medic, as a counselor in the Psych/Security unit of a prison for women, and as a criminal defense investigator. You can learn initial treatment of a traumatic amputation in a classroom, you can practice on an actor wearing a moulage, but it’s not the same as being confronted with a screaming, bleeding, panicked person who’s just had his arm torn off. You can teach somebody various interview techniques, but it’s not the same as finding a witness in a bar and trying to get them to talk to you. Real life is a lot weirder and slipperier. The only way to really learn to do a job is to do the job.

Potter was a passenger in the police squad car driven by her trainee. While they were on patrol, he saw a white 2011 Buick signal a right turn while it was in a left turning lane. He also noticed the vehicle’s registration tag on the licence plate was expired. There was also an air freshener hanging from the car’s rear view mirror, which technically could be considered an obstruction which might impair the driver’s vision. The news media focused almost exclusively on the air freshener, but the reality is that there were legal justifications for stopping the vehicle.

To be clear, they were all bullshit justifications–they’re the sort of things police officers often use to stop black/minority drivers. But, again, the only way to really learn to do a job is to do the job. Even if it was a bullshit justification, it was a legit teaching opportunity–a way for Potter to see how her trainee would handle a real life traffic stop. And also again, real life is a lot weirder and slipperier.

They stopped the car, did the usual “License and registration, please” business. This is what they learned: 1) Daunte Wright, the driver, didn’t have a driver’s license, 2) the car wasn’t registered to him or the woman passenger, 3) there was no proof-of-insurance, 4) a records check showed there was an open arrest warrant on Wright for failing to appear in court on weapons violation, 5) and a protective order had been filed against him by an unnamed woman. Even though it was a bullshit traffic stop, Potter and her trainee had probable cause to arrest Wright. In fact, until they determined whether or not the woman passenger Potter was the same woman who had the protective order against him, they’d have been negligent not to arrest him.

So they did. And then it all got weird and slippery. Wright decided to escape. In her 26 years as a police officer, Potter had never used either her pistol or her taser. When Wright broke away and got back in the car, she drew her pistol instead of her taser. Instead of tasing him, she shot and killed him.

Potter was just doing her job. But had what’s known in tort law as ‘a duty of care’. She had a legal obligation requiring her to adhere to a standard of reasonable care while performing any act that could foreseeably harm others. She had an obligation to know whether she was holding a pistol or a taser. And even though she clearly didn’t intend to kill Daunte Wright, he’s still dead. And Potter had to be held accountable for that.

This is exactly how the justice system should work. This is how it should work for every officer-involved incident. It’s about accountability, not revenge. It’s about a professional being held to a standard of behavior.

If a surgeon makes a mistake during an appendectomy, they have to be accountable for that. If the pilot of a commercial fishing vessel misjudges their speed and crashes the ship into a marina dock, they have to be accountable. If a bartender serves a clearly intoxicated person and that person dies in a traffic accident (or kills somebody else in a traffic accident), they have to be accountable. If a landscaper accidentally kills your lawn, they have to be accountable. And if a police officer kills a person in the line of duty–even if it’s unintentional–they have to be held accountable.

Kimberly Potter was almost certainly a good, solid police officer. She made a terrible mistake and Daunte Wright died as a result. It doesn’t matter that Wright was complicit in his own death, she remains responsible and accountable. I hope she gets a relatively light sentence, but at the heel of the hunt, she has to be accountable for it.

It’s about accountability, not vengeance.

This also applies to presidents.