Debates surrounding police brutality and race have been reignited in America after policeman charged with murder for shooting an unarmed black man.

Trigger warning: This post features explicit details of homicide that could be distressing for some readers.

The video says it all.

A police officer with a gun. An unarmed man running for his life.

The footage, captured by an bystander, appears to show police officer Michael Slager, 33, shooting the back of Walter Scott, 50, at least eight times as he tried to run away.

(Mamamia has chosen not to publish the footage.)

Michael Slager is white. His victim Walter Scott, who was originally pulled over for having a broken brake light, is black.

Slager has since been charged with murder.

Michael Slager has been charged with the murder of Walter Scott.

The North Charleston Mayor Keith Summey said authorities decided to charge Slager, after viewing a video of the incident, Reuters reports.

Officer Slager originally told fellow officers he feared for his life because Slager took his stun gun.

However, the footage shows the victim is unarmed and is running away as Slager shoots him in the back. It also suggests the officer drops something near the body of the victim, possibly that same stun gun.

After shooting him, the officer appears to approach Scott and handcuff him.

According to Fairfax Media, the shooting follows a spate of other incidents of a similar nature, sparking debates about lethal force used by police in the US, particularly against black men.  The footage has already promoted an outcry from the public and has been compared with a similar incident in Ferguson, USA, where a white police officer shot dead a black teenage boy. 

Reuters reports the FBI and US Justice Department have commenced separate investigations.

Do you think the officer used excessive force?