WATCH: The wife of man slain by American police fights back tears while calling for justice

Warning: footage of Louisana police shooting black man at point blank range results in large scale protests

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Image: Avon and Somerset Constabulary

Updated: 19.15

Quinyetta McMillan, wife of Alton Sterling who was shot and killed by police earlier this week, read out a statement to local media asking for justice against those who killed her husband.

She was surrounded by supporters and the couple’s 15-year-old son, Cameron, who broke down in tears while calling out for his father.

The entire speech can be watched below, which includes McMillan stating: “This is the image of a man who simply tried to earn a living. With that said, the individuals involved in his murder took away a man with children who depended on their daddy on a daily basis. As a mother, I have now been forced to raise a son who is going to remember what happened to his father. That I can’t take away from him. He is at an age of understanding, I hurt more for him and his loss. As a parent, one of the greatest fears is to see your child hurt and know there’s nothing you can do about it."

The fatal U.S. police shooting of a black man in Louisiana is to be investigated by federal Department of Justice.

Alton Sterling was shot and killed outside a convenience store where he was selling CDs by a Baton Rouge officer on Wednesday.

In a statement released earlier today, the U.S. Justice Department said: "the FBI's New Orleans Division has opened a civil rights investigation into the 37-year-old's death".

According to a running total by The Guardian, this is the 558th person killed by US police since the beginning of 2016.

In the 48-second mobile phone video below, police are shown to aggressive detain Sterling, tazing him and tackling him to the ground, before announcing "He's got a gun."

Both officers pull out their weapons, and the video shows one of the officers firing one round into Sterling at point blank range.

The camera then turns away, and we can hear several more shots being fired.

Warning: the footage is explicit and contains disturbing images.

The convenience shop owner, Abdullah Muflahi, told journalist Maya Lau of The Advocate how Sterling did indeed have a gun in his pocket, but never reached for or withdrew the weapon.

Not long after word was announce of the shooting, the hashtag #AntonSterling began trending on Twitter, while protesters appeared on the street near where the incident took place.