After the shooting which took place on Friday, Terence Crutcher could be seen lying on the side of the road, with blood pooling around his body, for nearly two minutes before anyone checked on him.
Police in Tulsa, Oklahoma, released a video on Monday showing an officer fatally shooting an unarmed black man who had his hands in the air.
Officer Betty Shelby shot Terence Crutcher, 40, whose sport utility vehicle broke down on Friday, police said. Crutcher was pronounced dead at a local hospital.
The US Justice Department said it was looking into the incident as a possible civil rights violation.
The case is the latest in a string of shootings of unarmed black men by US police that have raised questions of racial bias.
"We will achieve justice in this case," Tulsa Police Chief Chuck Jordan told a news conference, adding the release of video was done as a matter of transparency.
Jordan said he found the videos "very disturbing, very difficult to watch."
"Without a doubt we believe this was an unjustified shooting that should not have happened," the Crutcher family attorney Damario Solomon-Simmons said at a separate news conference, adding that they are seeking criminal charges.
The initial moments of Crutcher's encounter with police are not shown in the footage.
Shelby did not activate her patrol car's dashcam, said police spokeswoman Jeanne MacKenzie, and the ground-level video released on Monday came from the car of a second officer who arrived at the scene.
Initial police briefings indicated Crutcher was not obeying officers' commands, but MacKenzie she didn't know what Crutcher was doing that prompted police to shoot.
In one video shot from a police helicopter, Crutcher is seen with his hands in the air, followed by an officer with a drawn weapon. He then puts his hands on the vehicle.
One of the officers in audio from the helicopter says Crutcher is not following instructions. Another says "that looks like a bad dude too, could be on something." Crutcher then drops to the ground and a female officer can be heard on police radio saying "shots fired."
Crutcher is then seen on his back with what appears to be blood oozing from his torso.
In a police dashcam video, one officer with a weapon drawn trails Crutcher as he walks to the vehicle. A pop is heard and he falls a few seconds later.
"We think he may have just been Tasered," a man's voice is heard on a police radio. "Shots fired," a woman's voice then says.
One officer, identified as Tyler Turnbough, used his Taser on Crutcher, Tulsa police said, adding that Shelby fired her gun at the man.
Shelby has been placed on administrative leave, they said. She was not immediately available for comment.
Crutcher did not have a weapon on him or in his vehicle, police said, providing few details of the incident. They said Crutcher refused to follow officers' commands in the minutes before he was shot.
Left to die
After the shooting, Crutcher could be seen lying on the side of the road, blood pooling around his body, for nearly two minutes before anyone checked on him.
When asked why police did not provide immediate assistance once Crutcher was down, MacKenzie said, "I don't know that we have protocol on how to render aid to people."
The American Civil Liberties Union of Oklahoma, which also called for charges, said Crutcher was left to bleed while officers stood by.
The group's executive director, Ryan Kiesel, said Crutcher's death shows "how little regard" Tulsa police have for the community's minorities.
The US Department of Justice has launched a separate civil rights inquiry into the officers' use of force, US Attorney Danny Williams with the Northern District of Oklahoma said on Monday.
Crutcher's twin sister, Tiffany Crutcher, called for charges on Monday. "The big bad dude was my twin brother. That big bad dude was a father," she said.
"That big bad dude was a son. That big bad dude was enrolled at Tulsa Community College, just wanting to make us proud. That big bad dude loved God. That big bad dude was at church singing with all of his flaws, every week. That big bad dude, that's who he was."
The shooting comes just four months after former Tulsa County volunteer deputy Robert Bates was sentenced to four years in prison on a second-degree manslaughter conviction in the 2015 death of an unarmed black man.
Speaking Monday in Tulsa, civil rights attorney Benjamin Crump said Crutcher committed no crime and gave officers no reason to shoot him.
"When unarmed people of color break down on the side of the road, we're not treated as citizens needing help. We're treated as, I guess, criminals — suspects that they fear," said Crump.
"So I guess it's a crime now to be a big black man," Crump said. "My God, help us."