Walter Scott murder suspect Officer Michael Slager had prior complaint for use of excessive force against an unarmed black man

Supporters of the officer say he had 'served more than five years with the department without being disciplined' – but one man thinks he should have been

Picture of Michael Slager the policeman accused of using Taser on Wilson

The US police officer charged with murder after he shot unarmed black man Walter Scott had previously been the subject of an excessive force complaint, it has emerged.

Another black man who was also unarmed at the time, Mario Givens, says South Carolina police “didn’t listen” to his complaint about Officer Michael T Slager, who was filmed by a passer-by shooting eight times at Scott as he tried to flee.

“It could have been prevented,” said Givens, who claims he was beaten up and repeatedly Tasered by Slager despite offering no resistance in an incident in 2013.

Speaking to the Associated Press, 33-year-old Givens said he was at home when police came knocking looking for his brother, Matthew.

Instead of saying what they wanted, Slager forced the door and said: “Come outside or I'll Tase you,” Givens said.

“I didn't want that to happen to me, so I raised my arms over my head, and when I did, he Tased me in my stomach anyway.”

Givens told the AP that despite Givens’ brother’s ex-girlfriend – who had called police in the first place – telling them they had the wrong man, Slager and another officer dragged Givens out into the dirt anyway, Tased him a second time and then put handcuffs on him.

Walter Scott was a Coast Guard veteran and recently engaged to be married (ABC)

Givens said he filed a complaint the next day, and the ex-girlfriend Maleah Kiara Brown said she too spoke to a police supervisor.

But a brief report included in Slager's personnel file said a senior officer was assigned to investigate and, after a couple weeks, the case was closed with a note saying that Slager was “exonerated”.

A fund set up in support of officer Michael Slager has received hundreds of dollars in donations

“If they had just listened to me and investigated what happened that night, this man might be alive today,” Givens said.

A spokesperson for North Charleston police Spencer Pryor said the department now plans to review the case to see if its decision to clear Slager was correct.