The filmed moment has riveted the public's attention on when police can or cannot fire their weapons at a suspect who's in flight.
The South Carolina case raises the question in the same manner as another police shooting did last year in Ferguson, Missouri, where an officer killed another unarmed man, also black.
The Missouri officer was cleared of wrongdoing, though the incident inflamed a national discussion about race and police authority. But in South Carolina, Officer Michael Slager of North Charleston Police is now charged with murder in the slaying of Walter Scott.
As it turns out, laws about the use of police deadly force are relatively new, as recent as 30 years ago, experts say.
Can police shoot a fleeing suspect?
"Can an officer use deadly force involving a fleeing suspect which Mr. Scott seemed to be?" CNN legal analyst Avery Friedman asked.
"Contrary to popular belief, the answer is yes," said Friedman, a civil rights attorney and law professor
, "but the use of deadly of force is always conditional."
The fleeing suspect would have to pose a significant threat of death or of bodily harm to the officer or to others, according to Friedman and other experts.
"Unless the fleeing felon is a substantial risk to the life of the police officer or arguably to other people in the community, only then can you use deadly physical force to subdue them," said Paul Callan, a trial attorney
and former New York City prosecutor.
Gunfire is the last option for an officer.
"The application of deadly force ... is always the ultimate last resort," said Dennis Root, an expert on the use of police force
and a law enforcement trainer. "It is not objectively reasonable to shoot a fleeing subject who poses no immediate threat to the officer or others."
Has it always been that way?
Just harken back to those old TV movies when a felony suspect ran away from the police.
The officers in those old films immediately fired at the suspect.
Up until 1985, police had greater authority to use force against unarmed fleeing felons, experts said.
Then things changed.
"Up until 1985, the doctrine, called the fleeing felon doctrine, was that, if you committed a felony and the police were pursuing you, they could shoot you down if you tried to escape," Callan said.
"It arose out of the Middle Ages when all cases were punishable by death," he added. "So, you could shoot somebody if they were a felon or suspected of being a felon."
So what happened to change all that?
The U.S. Supreme Court limited the police use of deadly force against unarmed fleeing felons in a 1985 case called Tennessee v. Garner, according to William H. Freivogel, a legal expert and director of the School of Journalism at Southern Illinois University, who also covered the case back then and recently wrote about it on the website
of St. Louis Public Radio.
That 1985 case was about how Memphis police fatally shot 15-year-old Edward Garner after the officer saw the teenager climbing a fence to escape from a burglary, Freivogel wrote.
The teenager was unarmed and was found carrying $10 and a purse from the home.
The nation's high court ruled that Tennessee's laws justifying police deadly force against a fleeing suspect violated the Fourth Amendment, which bans unreasonable searches and seizures, Freivogel wrote.
"It is not better that all felony suspects die than that they escape. Where the suspect poses no immediate threat to the officer and no threat to others, the harm resulting from failing to apprehend him does not justify the use of deadly force to do so.
"It is no doubt unfortunate when a suspect who is in sight escapes, but the fact that the police arrive a little late or are a little slower afoot does not always justify killing the suspect. A police officer may not seize an unarmed, nondangerous suspect by shooting him dead," the justice wrote.
What should officers do in situations like the South Carolina case?
It's a complex question, and there are many ways to answer it, Root said.
"What they should do is completely dependent upon the situation the officer is facing and the information known to the officer at the time," Root said.
Root listed possible alternatives:
* The officer may pursue the individual and make physical efforts to take them into custody.
* The officer may follow the person and while maintaining sight of him, the officer can radio other officers in the area and coordinate a plan to apprehend the suspect.
* Lastly, if the person is fleeing and the officer knows the identity and residence of the suspect, police can take him into custody later.
Why can't police just shoot to injure?
This has been controversial in police training, said CNN senior legal analyst Jeffrey Toobin.
But police never fire a warning shot, he said.
"If you're going to fire your gun, discharge your weapon. You have to accept the risk that you're going to kill somebody," Toobin said. "If you're not prepared to kill someone, don't fire the gun.
"That's the lesson that most cops are taught. Because the risk, they say, is that if you start telling cops it's OK just to shoot at the arm, fire warning shots, you'll have people fire too often," he said.