We got sucker punched.

Not just the family of Walter Scott, who was shot in cold blood last year by a white South Carolina police officer. Not just black people, who can no longer shoulder this crucifix of injustice alone.

All of us — every single red-blooded one of us who maintained an iota of faith in the criminal justice system got sucker punched by a South Carolina jury.

The jury not only failed to convict Michael Slager of murder, but it couldn’t even settle on a lesser charge of manslaughter.

This was far more than a run-of-the-mill mistrial, which a black judge, ironically, was forced to declare. This was a grave and shocking miscarriage of justice.

It’s a stain on the criminal justice system that simply can’t be allowed to stand.

Yet, once again, we’ve been forced to accept that there really are two different standards of justice in America: one for cops, and one for everybody else.

OK, three standards — if you understand the dual justice system under which black Americans have suffered since Jim Crow.

What this embarrassing trial revealed, or reminded, is that all an officer has to say is “I feared for my life” — or words to that effect — to get off the hook.

It’s a vague standard that, for the most part, most of us can live with because we appreciate the dangerous work that officers do.

Shooting a fleeing, unarmed man in the back, however, doesn’t meet that standard, not by any stretch of a fair, objective and rational mind.

Nor did the officer’s self-defense explanation satisfy most jurors, who became hopelessly unable to reach a unanimous decision because at least one juror was unwilling to convict Slager.

I don’t know what that juror or any others who were undecided saw.

But a cellphone video erased any doubt that what Slager did that day not only should’ve got him fired, as it did, but it also should’ve got him convicted in a hurry.

Slager fired eight shots at a man running away from him.

He shot Scott three times in the back, once in the buttocks and once on the ear. Then, after he killed him, he left him lying face down on the ground like an animal. And based on the video, he dropped his stun gun by Scott’s body, apparently to give credence to his version of events.

Slager, predictably, put the blame on Scott for making himself a human target poster. After the officer stopped Scott for a broken taillight, Scott jumped out of his car and ran.

“In my mind at that time was, people don’t run for a broken taillight,” Slager testified. “There’s always another reason.”

In that moment, Slager became more than a cop. He morphed into a judge and jury.

After he and Scott allegedly scuffled over the officer’s stun gun, Scott took off running. And that’s when the officer exacted his punishment. He became the executioner.

“At that point,” he testified, “I pulled my firearm and pulled the trigger. I fired until the threat was stopped as I was trained to do.”

The fact that the officer can say that with a straight face and with every expectation of walking free is all you need to know about our system of justice in America.

The judge, bless his heart, even gave the jury an easy way out, allowing the 11 white jurors and one black one to consider a lesser charge of manslaughter, which meant prosecutors didn’t have to prove Slager acted out of malice.

Alas, that was not enough.

And justice, shamefully, was denied — not just for Walter Scott and his family, but for all of us who want to believe our criminal justice system works the way it should.

James Ragland is a columnist for the Dallas Morning News.