"My brother was gunned down like an animal"

Warning: The video above contains graphic content.

A white South Carolina officer was charged Tuesday and remains behind bars after disturbing cell phone video surfaced. The video captured Saturday morning purports to show the officer firing his gun eight times at an apparently unarmed black man as he ran away.

This is the latest in a series of racially charged police shootings around the country, and the victim's brother is speaking out, CBS News' Vicente Arenas reports.

Officer Michael Slager, 33, fired eight shots at the back of Walter Scott, 50, a father of four. Video shows Scott then falling to the ground.

South Carolina shooting video is telling evidence in cop's murder charge

As he lay motionless, the officer is heard on the video saying, "Put your hands behind your back, now."

"I thought that my brother was gunned down like an animal," Anthony Scott, the victim's brother, said. "It was just unbelievable to me to see that."

The amateur video, which CBS News legal analyst Rikki Klieman said is "telling evidence," paints a different picture than the one that first emerged Saturday.

Police said Slager pulled Scott over for a broken tail light. Authorities originally said Scott tried to run and the two men struggled over the officer's Taser. Slager said he feared for his life.

"Two-twenty-three, dispatch shots fired. Subject is down. He grabbed my Taser," Slager said over the police radio.

After the shooting, Slager can be seen picking something off the ground. He then appears to drop an object near Scott's body, though it's not clear what it is.

"If you did not have this video, would this police officer be behind bars this morning? Highly unlikely," Klieman said Wednesday on "CBS This Morning."

"My nephew who arrived on the scene first, he said, 'He's gone,'" Anthony said. "And when he said he's gone I'm like, 'That absolutely can't be true, that he's gone from a traffic stop.' I said, 'That can't be true.'"

An hour after city officials saw the footage, North Charleston Mayor Keith Summey announced Slager would be charged with murder.

"When you're wrong, you're wrong, and if you make a bad decision, don't care if you're behind the shield or just a citizen on the street," Summey said. "You have to live by that decision."

Klieman said there is a presumption of innocence until conviction "because everyone is entitled to it."

"But nonetheless, when we see this, if we are not fundamentally disturbed, then there is something wrong with us," she said.

While the Supreme Court has upheld officers' use of deadly force when there's probable cause that a suspect poses significant threat of death or serious physical injury, Klieman said "there's nothing we see in the video that leads us to believe, at this point in time, that there was ever a threat of danger to that officer or others."

Late Tuesday, Slager was denied bail. If convicted, the five-year police veteran could face the death penalty.

"What he took away was a member of the whole community," Scott family attorney Chris Stewart said. "And it was taken away because he didn't think anybody would care or that he would get caught."

Slager's former attorney released a statement saying it was "tragic event" but that the officer "believes he followed all the proper procedures and policies of the North Charleston Police Department." The attorney has since withdrawn from the case. Klieman said while it doesn't look good for Slager, his attorney could have withdrawn "for a thousand reasons."