Scott's mother, Judy, said the video that revealed her son's last moments was "the most horrible thing I've ever seen".
"I almost couldn't look at it to see my son running defencelessly, being shot," she said on ABC's Good Morning America. "It just tore my heart to pieces."
Police officer Michael Slager, 33, was charged on Wednesday with murder after the shooting, which happened on Sunday (Saturday US time) in the suburbs of Charleston, South Carolina. If convicted, he could face either life in prison or the death penalty.
The man who shot the video, meanwhile, came forward yesterday and told how he had feared for his own safety.
Feidin Santana told MSNBC that he initially considered deleting the video he recorded of Slager shooting at Scott eight times as Scott ran away, and thought about leaving North Charleston out of fear for his own safety.
Santana, a barber originally from the Dominican Republic, said he was walking to work when he saw police pursuing Scott and followed them to the area where the shooting unfolded. Santana said he heard the sound of a Taser being deployed and Scott began running before the shots were fired.
Santana said Scott appeared to have already been unconscious when the officer put handcuffs on him and walked away.
He said he later saw a police report about the shooting and knew that he had to come forward because the officer's account of what led to the shooting did not match what he recorded.
Santana said he showed the video to a friend after reading the report, and his friend agreed that he needed to come forward.
"I just put myself in the position of the family," Santana said, adding that he knew no charges would be filed against the officer who shot Scott if the video was not released.
Santana gave the video to Scott's family, who passed it on to the New York Times.
"What if there was no video? What if there was no witness, or 'hero' as I call him, to come forward?" L. Chris Stewart, a lawyer for Scott's family, told the Associated Press. "We didn't know he existed. He came out the blue."
Scott was struck five times - three times in the back, once in the buttocks and once in the ear. The video then shows the patrolman handcuffing the victim as he lies on the ground.
The North Charleston police force initially supported the officer, but on Wednesday North Charleston Mayor Keith Summey announced that Slager would be fired.
"When you're wrong, you're wrong," Summey said. "When you make a bad decision, I don't care if you're behind the shield or a citizen on the street, you have to live with that decision."
City officials yesterday promised to outfit the entire police department with body cameras which would mean all officers' actions would be caught on camera.
Scott's mother, who said she still believed there were good police officers, expressed disappointment that such a move was necessary.
"We're talking about cameras on the policemen," she told reporters. "It's a shame that you have to do that, because the policemen are supposed to protect us - we're supposed to be able to trust them."
- Independent, Washington Post
Fast action after latest shooting a sign of lessons learned as authorities try to keep peace
As footage of the shooting of Walter Scott has replayed endlessly on cable news and online, authorities have acted swiftly to show they have learned from past mistakes and to avoid protests like those seen in Ferguson, Missouri, last year.
"The community is very angry about it, so it's important to calm the community before things get out of hand," said James Johnson, president of the local chapter of the civil rights group National Action Network. "We don't want another Ferguson here."
Since last northern summer, the long shadow of Ferguson has extended over city after city as incidents in New York, Cleveland, Ohio and Madison, Wisconsin, sparked protests and outrage over how police use force on black men and boys. Now the focus is on North Charleston, the third-largest city in South Carolina, a place with more black residents than white that is patrolled by a predominantly white police force.
Mayor Keith Summey said yesterday his city had not turned into another Ferguson "because we did what is right".
"We turned the investigation over to an independent agency," Summey said at a news conference. "We gave them everything that we have."
Watch: Police chief: 'I was sickened by what I saw'
Local police gave the investigation to state law enforcement. The video also prompted the FBI and the Justice Department's civil rights prosecutors to announce a federal probe.
City leaders, legal observers and activists said the quick action in North Charleston spoke to a key lesson from Ferguson: act with urgency to try to keep the peace.
"I think we've all seen what happened when you seem to have clear facts and authorities don't move for a long time," said David Harris, a law professor at Pittsburgh University. "It's not good for anybody. That's the lesson of places like Ferguson."
In Ferguson, in the days after police officer Darren Wilson shot and killed unarmed 18-year-old Michael Brown, residents criticised how slowly police released basic information such as Wilson's name, while the grand jury process was slower than usual because of the way prosecutors showed evidence to jurors. In the end, the grand jury and the Justice Department opted not to bring any charges against Wilson.
"If you have compelling evidence and, by the way, the public has all seen it, maybe the lesson of earlier cases is let's move," Harris said. "No sense in waiting around for people to simply get angry."
Still, demonstrators took to the streets of North Charleston, some holding signs and placards. Outside City Hall, local organiser Muhiydin D'Baha repeatedly yelled "Eight shots in the back!" through a bullhorn. The crowd yelled, "In the back!" in response, aiming to coin a new phrase to supplant the "Hands up, don't shoot!" refrain that grew out of other officer-involved killings.
Ramon Roane said: "There is an atmosphere of racism [here] and we need to get rid of it."
- AP, Washington Post
Brother remembers a man who loved his kids
Walter Lamer Scott loved dancing and singing and watching the Dallas Cowboys football team. He had four children and just a few weeks ago, he proposed to his long-time girlfriend.
Records show Scott, 50, had been arrested up to 10 times, mainly for failing to pay child support or else not appearing in court.
Watch: Brother mourns death of Walter Scott
But his family and friends say he was not the sort of man to clash with police and if he had been trying to avoid an officer on the day he was killed, he may have been concerned about being detained for an outstanding childcare payment.
"When I heard on the radio what they said had happened, all I could think was that everyone would know the truth because I know it did not happen the way they said it happened," Scott's brother, Anthony Scott, told CNN.
"He had a very good relationship with his children. The older two had a different mother, who is deceased. But he brought them together as brothers and sisters and there was no separation. Now they have lost their father."
He said when he saw the video of his brother being shot, it appeared clear to him that he was trying to get away from the police rather than get involved in a confrontation.
"When I saw the video he was running for his life - not to be shot down, not to be tasered. I don't think my brother thought he was going to be shot. I don't think anyone could imagine that," he said.
Anthony Scott said he last saw his brother three weeks ago when they organised a surprise party to celebrate their parents' 50th wedding anniversary.
"It was a great celebration and a great surprise for my mother," he told CNN. "Now this [has] happened. It's so tragic, but I want America to know that we want this to stop."
- Independent
