WASHINGTON -- You thought, perhaps, that we were making this stuff up? That the whole "Black Lives Matter" thing was probably overblown? That the idea of African-American men having to fear routine encounters with the police was being exaggerated by self-serving activists?
Let's go to the videotape.
In North Charleston, South Carolina, last Saturday, a bystander happened to be watching --- and taking video with his cellphone -- as police officer Michael Slager killed a man named Walter Scott in cold blood.
The images are stomach-turning. The 50-year-old Scott, apparently unarmed, is running away. Slager draws his weapon and aims at Scott's back, firing again and again. The eighth bullet brings him down.
"Shots fired," Slager reported to the police dispatcher, according to authorities. "Subject is down. He grabbed my Taser."
In the cellphone video, Slager makes no attempt to revive the dying man. Instead, he goes back to the place where the encounter began, picks up an object and returns to drop it next to Scott's body. The object, difficult to identify in the video, is believed to be Slager's police Taser.
Imagine the narrative that might have emerged if the bystander, a man named Feidin Santana, hadn't happened along. A violent suspect struggled with Officer Slager, wrested control of the officer's Taser and threatened him with it. Fearful of his own safety and that of the community, Slager had no choice but to fire. The officer regrets the loss of Mr. Scott's life but did what he had to do.
After Ferguson, such an account might not have been taken at face value -- especially, I should note, in South Carolina, which has been much more aggressive in holding police officers accountable for fatal shootings. The most basic forensic examination would have shown that Scott was some distance from Slager -- and fleeing -- when he was shot. Investigators from the South Carolina Law Enforcement Division likely would have been skeptical of any claim that the officer feared for his life.
But what could anyone prove? In the end, detectives would have had the word of a police officer against that of a corpse. The truism is true: Dead men tell no tales.
Thanks to Santana's video -- and the testimony he likely will give -- justice has a chance. By midweek, Slager had been arrested and charged with murder.
Santana has said in interviews that initially there was a struggle between Slager and Scott, but Slager quickly "had control" of Scott and the situation. Scott "never grabbed the Taser of the police. He never got the Taser," Santana told NBC's Matt Lauer.
What started the whole thing? Slager pulled Scott over because he had a broken taillight on his aging Mercedes.
Michael Brown was walking in the middle of the street. Eric Garner was selling loose cigarettes. For three black men, these misdemeanors became capital offenses.
We don't know what happened before Santana arrived to bear witness, but I have to assume that Scott might have given him lip or otherwise expressed his displeasure. And given subsequent events -- eight shots fired at Scott's back -- I have to doubt that Slager initiated the encounter with an Officer Friendly approach.
Why wouldn't Scott just cooperate and do anything the officer ordered, however unjust or humiliating he felt it might be? I doubt we'll ever know. He reportedly owed back child support, and there was speculation that he wanted to avoid being jailed for that. I'm sure we'll soon learn of everything Scott ever did wrong in his five decades on Earth.
The fact is that not everyone who is ever stopped by a police officer is going to be happy about the experience. Yet black men run a tragically greater risk than others of having the encounter turn deadly.
How much more risk? As I wrote in a column last year, no one really knows. Incredibly, there are no authoritative, comprehensive statistics on police killings nationwide -- not even in the aggregate, let alone broken down by race.
But it doesn't take data analysis to realize that when police treat communities like occupied territory -- and routinely automatically classify black men as suspects -- the opportunity for tragedy grows exponentially.
Walter Scott's broken taillight was an excuse, not an offense. Slager knew that Scott had to be guilty of something. It was just a matter of finding out what that black man's crime might be.
Eugene Robinson is a nationally syndicated columnist.