A white South Carolina police officer has been charged with murder after he was filmed shooting an unarmed African American man who he pulled over for a broken brake light.

Office Michael Slager, 33, was charged with murder in a North Charleston court on Tuesday, and could face either life in prison or the death penalty.

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The case has sparked widespread anger and protests across the state in the wake of a number of police shootings of black men, including 18-year-old Michael Brown in Ferguson, Missouri, last year.

Mr Slager said he shot 50-year-old Walter Scott on Saturday because the father-of-four had lunged for his taser gun, and he feared for his life.

Michael Slager was charged with murder. Photo: AAP

Video filmed by an innocent bystander which emerged on Youtube, however, revealed Mr Scott had been trying to flee and run away from Mr Slager when he was shot in the back eight times.

Mr Slager is then seen walking over to Mr Scott’s body and handcuffing him and he lay bleeding.

The bystander who filmed the disturbing scenes on his way to work told Time he knew immediately the power of what he had recorded.

“I knew right away, I had something on my hands,” Feidin Santana said.

“I were to have a family member where that happened I would like to know the truth.”

Speaking at a highly-charged press conference on Wednesday, an emotional North Charleston mayor Keith Summery said the city had moved to quickly fire Mr Slager.

He vowed to speed the introduction of body cameras so each of the town’s police officers could record incidents.

The victim’s father, Scott Walter Snr, said his family was devastated but was grateful the video had emerged.

“The way he was shooting that gun, it looked like he was trying to kill a deer or something running through the woods,” Mr Walter told The Today Show.

“I don’t know whether it was racial or something wrong with his head or what.

“I thank God they had the video. God has my back. When I saw it, my heart was broken.”

The killing of unarmed black teen Michael Brown last August was a catalyst for protests and a renewed debate on racism and police tactics.

A jury chose not to indict a Ferguson, Missouri, police officer for the shooting.

Since then, other killings by police have prompted protests in cities from coast to coast.

The US Justice Department unearthed what it called damning evidence of racism in the Ferguson police force after Brown’s shooting and says it will take appropriate action in the North Charleston case.

WARNING: SOME VIEWERS MAY FIND THE BELOW VIDEO DISTURBING.

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– with AAP