CRI听力:S. Carolina Officer Has History of Using Excessive Force

It's been revealed a South Carolina police officer charged with the murder of an unarmed suspect had previously been investigated for allegedly using excessive force.

Authorities are now re-investigating officer Michael Slager's use of a stun gun in a case dating back to 2013.

Slager is charged with murdering 50-year-old Walter Scott.

Scott, an unarmed black man, was shot in the back after running away from Slager following a brief scuffle.

The victim was originally pulled over by Slager for a routine traffic violation.

Slager is being held without bail and faces up to life in prison if convicted.

Meanwhile, civil rights leaders are demanding the North Charleston Police Department create a citizens review board to look at other complaints against its officers.

Dot Scott is the head of the local branch of the NAACP (National Association for the Advancement of Colored People).

"When the evidence at the scene does not support what the officer says and yet, time and time again, that's what's accepted, that tells you that it is a business as usual. When an officer at 9:30 in the morning on a Saturday feels comfortable enough in open space to fire and execute another citizen and then boldly tamper with the evidence, that tells you there's a culture here that it's alright."

The shooting of Walter Scott is the latest in a string of high-profile police shootings involving black victims and white police officers in the United States over the past year.

The incidents have stirred debate across the country about how police used their weapons, as well as racial profiling.