Protests have been held in South Carolina over the fatal shooting of an unarmed man as he ran away from police.
Officer Michael Slager was charged with murder and sacked after video emerged of him shooting Walter Scott multiple times in the back following a scuffle.
He was arrested when authorities reviewed mobile phone video of the shooting, which took place on Saturday.
The incident has been widely condemned, and the US Department of Justice and the FBI are investigating.
Cries of "Black lives matter!" rang out as about 50 protesters joined local politicians outside City Hall in North Charleston on Wednesday morning.
"We cannot sit still and be quiet anymore. This is our season to speak!" said one woman who commanded the crowd's attention.
At the protests - Aleem Maqbool, BBC News
The protests here have been small, unlike those that followed the killing of Michael Brown, the unarmed teenager in Ferguson last year.
But just like in Ferguson, African Americans here talk about feeling discriminated against by the police for years.
This time there has been unusually swift action against the police officer involved, but the protesters are not convinced charges would have happened without the video evidence.
It seems the killing of Walter Scott has once again exposed the huge issues of race and policing in this country.
Appearing on ABC's Good Morning America breakfast programme, Mr Scott's mother, Judy Scott, described the video as "the most horrible thing I've ever seen".
"I almost couldn't look at it to see my son running defencelessly, being shot. It tore my heart to pieces," she said.
Other members of the family said they were grateful the video came to light and the authorities had acted quickly in response.
Mr Slager was fired from the force on Wednesday, as North Charleston Police Chief Eddie Driggers said he was "sickened" by the video.
The incident on Saturday began after Scott's car was stopped for having a broken rear light, local media reported.
A video of the incident published by the New York Times shows a brief scuffle before Scott begins running away.
The video then shows the officer firing several shots at Scott, who falls to the ground.
Mr Slager said at the weekend, through his lawyer, that he feared for his safety as Mr Scott had tried to grab his stun gun.
The same lawyer, David Aylor, told the Daily Beast he dropped Mr Slager as a client after the video become public.
The police officer appeared without a lawyer at his first court hearing on Tuesday. He could face up to life in prison if convicted of murder.
Mr Scott had four children, was engaged and had been honourably discharged from the US Coast Guard.
The Post and Courier newspaper of Charleston reported that Mr Scott had been arrested about 10 times, mostly for failing to pay child support or not showing up for court hearings.
The shooting occurred as heightened scrutiny is being placed on police officer shootings, particularly those that involve white officers and unarmed black suspects.
A grand jury declined to indict Ferguson, Missouri officer Darren Wilson over the fatal shooting of Michael Brown last August, leading to nationwide protests.
A national debate followed into the police use of lethal force and a White House task force has recommended a host of changes to police practices.
Meanwhile another video emerged on Wednesday, this time of the deadly shooting of a black man in Miami.
Lawyers for the family of Lavall Hall, 25, say he was shot on 15 February after his mother called police for help after a psychotic episode.
US police: Controversial recent killings
April 2015: Walter Lamer Scott, 50, is shot eight times in South Carolina as he runs away from Officer Michael Slager. Mr Scott dies at the scene. The shooting is captured on video and Mr Slager is charged with murder.
December 2014: Jerame Reid, 36, is shot dead during a routine traffic stop in New Jersey. An officer claims Mr Reid was reaching for a gun, but video footage seems to suggest he was attempting to step out of the car, hands raised.
November 2014: Tamir Rice, a 12-year-old boy, is shot dead in a playground by Cleveland police after a local resident reports he is pointing a gun at passers by. The gun turns out to be a toy. A grand jury will decide whether police will face charges.
August 2014: Michael Brown, an unarmed 18-year-old, is shot dead by Officer Darren Wilson in Ferguson, Missouri. The shooting leads to protests, first in Ferguson and later nationwide. A grand jury decides not to charge Mr Wilson.
July 2014: Eric Garner, an asthma sufferer, is stopped by police in New York and placed in a chokehold after refusing to be handcuffed. He dies despite repeatedly telling officers he cannot breathe. No police are charged.
March 2014: James Boyd, an unarmed homeless man camping in Alberquerque, is shot dead by two officers. Video of the incident leads prosecutors to say the officers acted with "deliberate intention" and they are charged.