Two weeks ago, a black woman driving alone in Princeton, Louisiana, was pulled over for no apparent reason.

But she was not shot and killed. Or hauled from her car and body-slammed. Or even arrested for getting snippy.

The officer explained that she was driving under the speed limit, something he said drivers do when they are tired or inebriated. He said he just wanted to make sure she was OK.

“And as he said that,” said Ayanna Reid Cruver in a video posted to Facebook, “I just broke down crying,”

She cried again, recounting it. “I told him, ‘I was so scared.’ I knew he felt awful that I was that scared. … I never thought that in that situation I would feel fearful, but I legitimately felt horrified.”

The officer, she said, begged her not to cry. He even gave her a hug. But Cruver was still so shaken she had to get off the freeway and pull over to compose herself.

Her video has been viewed 3.3 million times.

To judge from the comments, many people were moved and troubled by it. But some weren’t. At least one individual smugly assured Cruver that so long as she obeys an officer, she has no reason to fear. Perhaps that’s true in his world, but African Americans live a different truth.

After all, Levar Jones was obeying when he was shot. Lateef Dickerson was obeying when he was kicked in the face. And Tamir Rice never had a chance to obey.

It’s no surprise Cruver’s video discombobulates some of those for whom police brutality is only a news story: It offers stark testimony of the damage done to policing when accountability is not required. As such, that clip should be required viewing for every cop in America, every chief who ever stood behind a bad officer, every prosecutor who ever looked the other way, every juror who gave a cop benefit of the doubt when there was no doubt, every judge for whom equality before the law was only words to say.

Consider the three cases noted above. Levar Jones’ assailant pleaded guilty in March of last year, but has yet to be sentenced. A jury cleared the cop who broke Lateef Dickerson’s jaw. Tamir Rice’s killer was never even tried.

The damage of such failures is bigger than those three cases or the hundreds that preceded them. Where there is no accountability, there can be no trust. When law-abiding people have legitimate reason to fear even a traffic stop, the world becomes more dangerous, both for police and the communities they serve.

Last week, Omaha Police Chief Todd Schmaderer called for two officers to be fired after they tasered a mentally ill man 12 times and he died. Last month, Balch Springs, Texas, Police Chief Jonathan Haber sacked an officer who shot into a moving car, killing an unarmed 15-year-old boy.

The sad thing is, such episodes of police accountability are rare enough that they stand out, that you remember them. They even seem morally heroic. And they should not.

When he was stopped last year for speeding, Tony Lee, a Washington-area preacher, was happily surprised to find the officer friendly and professional. Talking with a friend, Lee, who is black, called the encounter a “blessing.” The friend, a white police chief in another jurisdiction, was angry at that, reminding Lee that anyone who gets a ticket — even a deserved one — has a right to be upset. “But,” said the chief, “you’re just happy you’re (still) living. That’s not the way it should be.”

No, but that is the way it is. And because of the way it is, a simple traffic stop left Ayanna Cruver terrified.

“I shouldn’t have had to feel this,” she said.

Leonard Pitts Jr. is a columnist for the Miami Herald. Readers may write to him via email at: lpitts@miamiherald.com.