The Democrats' likely presidential candidate Joe Biden has demanded justice over the killing of an unarmed black man in the US state of Georgia.
Mr Biden said his heart went out to the family of Ahmaud Arbery.
Mr Arbery, 25, was jogging in February when confronted by an ex-policeman and his son. Video purported to show the shooting emerged online on Tuesday.
A district attorney in Georgia has now ruled that a grand jury should decide whether charges should be brought.
An earlier decision by a prosecutor in the Brunswick jurisdiction argued there was no probable cause to arrest Gregory McMichael, 64, and his son Travis, 34.
More than 100 people took part in a protest in Brunswick on Tuesday night, demanding justice for Mr Arbery.
How did Arbery die?
Mr Arbery was out running in the Satilla Shores neighbourhood of Brunswick in Georgia's Glynn County early in the afternoon on 23 February.
In a police report, Gregory McMichael says he saw Mr Arbery and believed he resembled the suspect in a series of break-ins.
He and his son armed themselves and pursued him in a pick-up truck.
In the police report, Gregory McMichael says he and his son had said "stop, stop, we want to talk to you" and that Mr Arbery had attacked his son. Shots were fired, with Mr Arbery falling to the street.
Mr Arbery's mother, Wanda Cooper Jones, said police told her her son had been involved in a burglary before the incident, but the family say they do not believe the keen jogger had committed a crime and he was unarmed.
A number of calls were made to the emergency services around the time of the confrontation, CBS reports. In one 911 call, a neighbour said a black man was seen at a home under construction in the area.
When asked what the man was doing now, the caller said "running down the street".
What does the video show?
The 36-second video is shot from a vehicle following the pick-up truck said to be involved in the incident.
It shows a man jogging and then approaching the stationary pick-up from behind. He tries to bypass the truck and then is seen struggling with a man carrying a shotgun. There is muffled shouting and shotgun shots are heard.
A second man is standing in the bed of the pick-up. The second man is then shown with a pistol standing alongside the other armed man with the jogger no longer in view.
Mr Arbery's mother told CBS on Wednesday that the video was too painful for her to watch immediately, but that she hoped the video "proves that my son was not committing a crime. He was out for his daily jog and he was hunted down like an animal and killed."
What have Mr Biden and other officials said?
Joe Biden sent out a tweet saying: "The video is clear: Ahmaud Arbery was killed in cold blood. My heart goes out to his family, who deserve justice and deserve it now. It is time for a swift, full, and transparent investigation into his murder."
A statement from Lee Merritt, a lawyer for Mr Arbery's family, said: "This is murder. The series of events captured in this video confirm what all the evidence indicated prior to its release."
Tom Durden, the district attorney for the Atlantic Judicial Circuit, decided on Tuesday that a grand jury should be involved.
"After careful review of the evidence," he wrote in a statement, "I am of the opinion that the case should be presented to the grand jury of Glynn County for consideration of criminal charges."
Governor Brian Kemp tweeted that "Georgians deserve answers".
The McMichaels have not been charged and have so far declined to comment. They have not responded to the video.
The New York Times said it had obtained a letter in which a prosecutor had earlier argued there was not sufficient probable cause for arrest because the pursuers were legally carrying firearms, were within their rights to follow "a burglary suspect" and were able as private persons to "arrest an offender if the offence is committed in his presence or within his immediate knowledge".
Mr Merritt told CNN: "The only thing they have ever said is ... that Ahmaud stopped by a house that was under construction and he looked through the window. We don't know if that happened or not, but even if that did happen that is not a felony that would invoke the citizen's arrest statute that would make this allowable."