The governor of the northern US state asked the White House to order a federal probe last night's shooting in FalconHeights, near Minneapolis, as calls mounted for justice for the 32-year-old victim Philando Castile.
A four-year-old girl witnessed the shooting from the back seat of the car, as her mother -- Castile's girlfriend -- livestreamed the bloody aftermath while an officer pointed his gun through the window.
Speaking to reporters outside the governor's mansion in St. Paul, after a night in police custody, Diamond Reynolds repeated what she asserted in the shock footage: that Castile was shot "for no reason."
"Not one shot. Not two shots. Not three shots. Not four shots. But five shots," she said in a forceful appeal for justice to be served.
Pulled over for a broken tail light, Castile informed the officer he was carrying a licensed gun, Reynolds said, and was shot as he reached for his license and registration.
She said the officer, whom she described as an Asian male, made conflicting demands of Castile -- both that he keep his hands in the air and that he identify himself.
"Nothing within his body language said intimidation. Nothing within his body said, 'Shoot me.' Nothing within his language said, 'Kill me I want to be dead."
Reynolds said her phone had been seized as evidence and voiced fear of a police cover-up.
"They're gonna tamper with evidence," she told reporters. "They're gonna do whatever they have to do to cover their butts."
But Governor Mark Dayton pledged to push for a full and independent inquiry by the Department of Justice -- which is already investigating the police shooting of a black man caught on video two days earlier in Louisiana.
"Justice will be served in Minnesota," Dayton said.
America's debate on police use of lethal force, especially against young black men, was set to hit fever pitch as a fourth officer went on trial Thursday in one of the highest-profile such cases of recent years.
Three officers so far have escaped conviction in the case of Freddie Gray, a young black man who died last year in Baltimore after suffering spinal injuries in the back of a police van.
On Tuesday this week, a black father of five, 37-year-old Alton Sterling, was pinned to the ground and shot several times at point blank range in Baton Rouge, Louisiana, prompting the launch of a federal civil rights probe.
Shocked family members demanded justice for Castile, a school cafeteria worker, whose mother described him as a law-abiding citizen who kept out of trouble.