An unarmed black dad was shot dead by police in California who mistook his mobile phone for a gun.
Stephon Clark, 22, was in his own backyard when officers opened fire 20 times claiming they “feared for their safety”.
They then waited more than five minutes until backup arrived before approaching Mr Clark’s body.
Footage from police bodycams was released which showed the two officers running after Mr Clark with their flashlights yelling “show me your hands” and “gun” before they shoot him.
Police in Sacramento had been called to reports of a black male having smashed three car windows in the area.
Officers saw a suspect shatter the sliding glass door of a house and then jump a fence into another yard.
After the shooting, investigators found a mobile phone next to Mr Clark but no firearm or weapon.
The mayor of Sacramento said he was “horrified” by the video which has sparked fresh outrage at the treatment black people face at the hands of police in the US.
More than 200 demonstrators gathered on Thursday to denounce the shooting in a protest organised by the Black Lives Matter movement.
Organizers described shooting deaths of black people by police as disturbingly commonplace.
“Like any compassionate person, I was horrified by the death of a young Sacramento man who we later found out had two kids,” Mayor Darrell Steinberg said at a news conference.
“What was my reaction? It was horrible.”
Protesters marched into the city hall lobby shouting, “It’s a phone, not a gun” and demanded a meeting with the police chief.
Mr Clark, a dad of two, was staying at his grandparents’ home at the time of shooting.
Sequita Thompson, his grandmother, was in the dining room when she heard the shots.
“The only thing that I heard was pow, pow, pow, pow, and I got to the ground,” she said.
Her husband phoned police to report gunshots and the pair were interviewed for several hours but were not told it was their grandson involved and that he was dead.
It wasn’t until Mrs Thompson opened the curtain to look in the backyard that she saw Mr Clark’s body.
“I started screaming,” she added.
The shooting is the latest in a series of killings of unarmed black men by police across the United Stated since 2014 that has sparked a national debate about racial bias in the criminal justice system and the use of lethal force.
The mayor said the city will review police protocol for aiding a person who is lying still.
The shooting was in the backyard of Clark’s grandparents’ home, where he had been staying, according to the Sacramento Bee newspaper, which spoke to his relatives.
The Sacramento County District Attorney’s Office was investigating the shooting.