The witness hailed as a hero for capturing the shooting of Walter Scott on camera has come forward to speak publicly about the incident for the first time.

Identified by NBC News as Feidin Santana, the man whose video made headlines around the world described the “emotional” moment he handed his vital evidence over to the Scott family.

Mr Santana’s video showed 33-year-old Officer Michael Slager shooting Mr Scott in the back as he runs away, and the witness said he only came forward when the police’s version of events – that Mr Scott had seized control of the officer’s Taser – appeared in the media.

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

Lawyers for the Scott family have said Mr Santana’s eyewitness evidence will be central to the prosecution of Officer Slager, who has been fired from the police force in North Charleston, Carolina and charged with murder.

Speaking to NBC News, he described what you don’t see in the video: “There was a struggle, they were down on the floor before I started recording.

“I remember the police [officer] had control of the situation. He had control of Scott. And Scott was trying just to get away from the Taser,” Mr Santana said.

“I heard the sound of the Taser – Scott had been Tased before I started recording.”

Mr Santana said that as soon as Mr Slager started shooting Scott in the back he “knew right away that I had something in my hands”.

He handed the evidence over to Mr Scott’s family, whose lawyers in turn gave it to prosecutors and the media. Describing the moment he showed it to the family, Mr Santana said: “Their reaction to me was very emotional.

In pictures: Walter Scott shooting Show all 12 1 /12 In pictures: Walter Scott shooting In pictures: Walter Scott shooting Walter Scott shooting Scott is pictued trying to escape from Slager In pictures: Walter Scott shooting Walter Scott shooting Slager points his weapon on Scott as he runs away In pictures: Walter Scott shooting Walter Scott shooting Slager is seen apparently firing on Scott Reuters In pictures: Walter Scott shooting Walter Scott shooting Scott is falling over after the eighth shot is fired In pictures: Walter Scott shooting Walter Scott shooting Slager stands over Scott right after the shooting Reuters In pictures: Walter Scott shooting Walter Scott shooting Slager appears to handcuff Scott's lifeless body In pictures: Walter Scott shooting Walter Scott shooting Another officer arrives at the scene and inspects Scott's body In pictures: Walter Scott shooting Walter Scott shooting More officeres arrive at the scence In pictures: Walter Scott shooting Walter Scott shooting In pictures: Walter Scott shooting Walter Scott shooting Brothers of Walter Scott, Rodney Scott (L) Anthony Scott (R) appear at a news conference in Charleston after the shooting AP In pictures: Walter Scott shooting Walter Scott shooting Walter Scott in the Coast Guard uniform ABC In pictures: Walter Scott shooting Walter Scott shooting Officer Michael Slager has been charged with murder over the incident EPA

“[Before handing it over] I thought about his [Scott’s] position, I thought about their situation... If I were to have a family member who that would happen [to], I would like to know the truth.”

The Scott family’s lawyer L Chris Stewart said on Wednesday that Mr Santana would be speaking to a press conference at some point, and said his actions “should be respected throughout this country”.

“We have to really recognise the strength and fortitude and fearlessness that it took to come forward when you know you just filmed a police officer murder somebody,” Stewart told reporters. “That’s the kind of person that needs to be duplicated.”

Asked if he was happy that his bravery led to Officer Slager’s arrest, Mr Santana told NBC: “It’s not something that anyone can feel happy about, but he made a bad decision, and in life you pay for your decisions.”

Meanwhile, an online fundraising appeal on behalf of the officer has sparked further controversy for the Charleston community.

Raising $300 as of Thursday morning, the Michael T Slager Support Fund has received more than 100 comments, many of them critical.