Investigation launched after video footage of black man shot in scuffle with two white police officers released
The US Justice Department has opened a civil rights investigation into the video-recorded killing of a black man who was shot as he scuffled with two white police officers.
The authorities moved quickly to keep tensions from boiling over after Alton Sterling died in the incident in Baton Rouge, Louisiana.
One law enforcement official said a gun was taken from the 37-year-old after he was killed in the car park outside a convenience store where he regularly sold home-made music CDs from a folding table.
It was not clear from the murky mobile phone footage whether Mr Sterling had the gun in his hand or was reaching for it when he was shot.
A witness said he saw police pull a gun from Mr Sterling's pocket after the shooting.
The shooting in the Louisiana capital - and shocking videos that found their way all over the internet - set off angry protests in the city's black community and brought calls for an outside investigation.
It came at a time when law enforcement officers across the country are under close scrutiny over what some see as indiscriminate use of deadly force against blacks.
Moving quickly just one day after the shooting, Democratic Governor John Bel Edwards asked the Justice Department to take the lead in the investigation.
"I have very serious concerns. The video is disturbing, to say the least," the governor said.
Mr Edwards also met black community leaders to reassure them about the investigation and to ask for their help in keeping protests peaceful.
He expressed hope that once the community sees that the shooting is "going to be investigated impartially, professionally and thoroughly ... the tensions will ease".
Democratic presidential candidate Hillary Clinton called the shooting a tragedy and said trust between police and the communities they serve needs to be rebuilt.
"Something is profoundly wrong when so many Americans have reason to believe that our country doesn't consider them as precious as others because of the colour of their skin," she said.
Baton Rouge Police Chief Carl Dabadie Jr said Mr Sterling was armed - he did not specify the type of weapon - but that there are still questions about what happened.
"Like you, there is a lot that we do not understand. And at this point, like you, I am demanding answers," Mr Dabadie said, calling the shooting a "horrible tragedy".
Mr Sterling was confronted by police after an anonymous caller reported being threatened by someone with gun outside the store, the authorities said.
In the mobile phone video taken by a community activist and posted online, one of the officers tackles Mr Sterling, and the two officers pin him to the pavement.
Someone yells "he's got a gun! Gun!" and one officer pulls his weapon from his holster. After some shouting, what sounds like a gunshot can be heard. The camera pulls away before more shots were heard.
The officers, identified by the chief as Blane Salamoni, a four-year member of the department, and Howie Lake II, who has been on the force for three years, were placed on administrative leave, standard department procedure.
The authorities would not say whether one or both officers fired their weapons or how many times.
The store owner, Abdullah Muflahi, released a video that he said he shot from a slightly different angle.
He said Mr Sterling was not holding a gun during the shooting but that he saw officers remove one from his pocket afterwards. His video shows an officer reaching into Mr Sterling's pocket to grab an object.
Mr Muflahi said an officer fired four to six shots into Mr Sterling's chest.
Hundreds protested on Tuesday night, and demonstrators gathered again on Wednesday, when a vigil drew hundreds of mourners singing, praying and calling for justice.
Quinyetta McMillon, the mother of Mr Sterling's teenage son, trembled as she read a statement outside City Hall, where dozens of protesters and community leaders had assembled.
Her son, Cameron, 15, broke down in tears and was led away sobbing as his mother spoke.
She described Ms Sterling as "a man who simply tried to earn a living to take care of his children".
Baton Rouge, a city of about 229,000, is 54% black, according to census data, and more than 25% of its people live in poverty.
The Justice Department will look into whether the officers wilfully violated Mr Sterling's civil rights through the use of unreasonable or excessive force.
Similar investigations, which often take many months, were opened after Michael Brown's shooting in Ferguson, Missouri, and following Eric Garner's chokehold death in New York City.
Investigators must meet a high legal burden to bring a civil rights prosecution, establishing that an officer knowingly used unreasonable force under the circumstances and did not simply make a mistake or use poor judgment.